WO2019060486A1 - Process for the production of organohydridochlorosilanes from hydridosilanes - Google Patents

Process for the production of organohydridochlorosilanes from hydridosilanes Download PDF

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WO2019060486A1
WO2019060486A1 PCT/US2018/051860 US2018051860W WO2019060486A1 WO 2019060486 A1 WO2019060486 A1 WO 2019060486A1 US 2018051860 W US2018051860 W US 2018051860W WO 2019060486 A1 WO2019060486 A1 WO 2019060486A1
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general formula
reaction
group
formula
iii
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PCT/US2018/051860
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French (fr)
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Norbert Auner
Tobias SANTOWSKI
Alexander G. STURM
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Momentive Performance Materials Inc.
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Publication of WO2019060486A1 publication Critical patent/WO2019060486A1/en

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
    • C07F7/02—Silicon compounds
    • C07F7/08—Compounds having one or more C—Si linkages
    • C07F7/12—Organo silicon halides
    • C07F7/121—Preparation or treatment not provided for in C07F7/14, C07F7/16 or C07F7/20
    • C07F7/125—Preparation or treatment not provided for in C07F7/14, C07F7/16 or C07F7/20 by reactions involving both Si-C and Si-halogen linkages, the Si-C and Si-halogen linkages can be to the same or to different Si atoms, e.g. redistribution reactions

Definitions

  • the present invention relates to the production of hydridosilanes, in particular to the production of hydridochlorosilanes, in particular of mono- and dichlorohydridosilanes in particular, methylchlorohydridomonosilanes selected from Me 2 Si(H)CI, MeSi(H)CI 2 , and MeSi(H) 2 CI. More specifically, the invention relates to a process for the production of hydridochlorosilanes starting from hydridosilanes.
  • Organohydridosilanes are useful starting materials in synthetic organosilicon chemistry, and therefore constitute an industrially valuable class of compounds.
  • Such organosilanes bearing both chloro- and hydrido substituents constitute attractive starting materials in synthesis due to their bifunctional nature, which means they have functional groups of different reactivities.
  • the chloride substituent is a better leaving group than the hydride group and allows, for instance, the controlled addition of further monomeric or oligomeric siloxane units with retention of the Si-H bond under mild conditions, thereby rendering said chlorohydridosilanes useful as blocking and coupling agents in the synthesis of defined oligo- and polysiloxanes.
  • Such compounds generally find a wide range of applications, for instance for the manufacture of adhesives, sealants, mouldings, composites and resins for example in the fields of electronics, automotive, construction and many more.
  • US 2013/172593A1 and US 2013/172594A1 relate to a catalytic process for producing an organohalosilane monomer composition from a high-boiling residue. In such process no hydridoorganylsilanes (with no chlorine substituent) are reacted.
  • US 2012/1 14544 A1 relates to organic chlorohydrosilanes, which is prepared by reacting a dichlorosilane with a trichlorosilane in the presence of a quaternary organic phosphonium salt catalyst. Also in such process no hydridoorganylsilanes (with no chlorine substituent) are reacted.
  • JP H03 24091 A relates to a process of manufacturing R 2 SiHCI from R 2 SiCI 2 . Also in such process no hydridoorganylsilanes (with no chlorine substituent) are reacted.
  • Si-H moieties present in hydridochlorosilanes can be utilized for post-synthesis modifications and functionalisations, for instance for the introduction of organic residues to polyorganosiloxanes or for cross-linking by hydrosilylation reactions, which is desirable in various kinds of compositions containing polyorganosiloxanes.
  • Synthesis of functionalized polysiloxanes starting with transformations via the Si-H bond(s) followed by hydrolysis or alcoholysis of the Si-CI bond(s) and optionally condensation for the formation of polysiloxanes is also viable.
  • organohydridosilanes serving as starting materials.
  • organosilicon hydrides and organosilicon compounds containing both Si-H and Si-CI bonds from organosilicon halides, in particular, organosilicon chlorides, is also known in the art.
  • the problem to be solved by the present invention is the provision of a process for the production of in particular mono- and dichlorohydridoorganosilanes from in particular hydridosilanes.
  • the present invention relates to a process for the manufacture of monosilanes of the general formula (I):
  • R is an organyl group
  • x 1 to 3, preferably 1 to 2,
  • y 1 to 3, preferably 1 to 2
  • z 0 to 3, preferably 1 to 2
  • n 0 to 5
  • At least one silane of the formula (II), (III) or (IV) has at least one chlorine substituent at the silicon atom
  • silanes of the formula (II), (III) or (IV) submitted to the reaction is selected from the group consisting of:
  • R 1 is hydrogen or an organyl group, which can be the same or different, preferably R 1 is R as defined above, more preferably an aromatic group or aliphatic hydrocarbon group, even more preferably a n-alkyl group, and most preferably a n-butyl group,
  • R 1 is hydrogen or an organyl group and can be the same or different, preferably R 3 P, wherein R is as defined above and can be the same or different, such as preferably PPh 3 ,
  • R 1 is hydrogen or an organyl group and can be the same or different, preferably R 3 N, wherein R is as defined above and can be the same or different, such as preferably n-Bu 3 N,
  • methylimidazoles such as 2-methylimidazole, 4- methylimidazole and 1- methylimidazole
  • R 1 4 NCI wherein R 1 is hydrogen or an organyl group and can be the same or different, preferably R4NCI, wherein R is as defined above and can be the same or different, such as preferably n-Bu 4 NCI
  • R" R" wherein the substituents R" are independently selected from organyl substituents (R) as defined according to the invention, hydrogen (H) and chlorine (CI), and
  • the meaning of the term "empirical formula” intends to mean that the formulae do not represent the structural formulae, but just sum up the chemical groups or atoms present in the molecule.
  • the empirical formula R2S12CI4 may comprise the structural formulae: CI CI CI CI
  • the process of the present invention requires the use of at least one organohydridosilane (with no chlorine substitution) as starting material.
  • any compound, material or substance which is expressly or implicitly disclosed in the specification and/or recited in a claim as belonging to a group of structurally, compositionally and/or functionally related compounds, materials or substances includes individual representatives of the group and all combinations thereof. While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art may envision many other possible variations that are within the scope and spirit of the invention as defined by the claims appended hereto.
  • one compound of the general formula (I) or a mixture of more than one compound of general formula (I) is formed.
  • the substituent R represents an organyl group, which is bound to the silicon atom via a carbon atom, and which organyl group can be the same or different.
  • the organyl group is an optionally substituted, more preferably unsubstituted group, which is selected from the groups consisting of: alkyl, aryl, alkenyl, alkynyl, alkaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, cycloaralkyl, cycloaralkenyl, and cycloaralkynyl, even more preferably selected from alkyl, cycloalkyl, alkenyl and aryl, even further preferred selected from methyl, vinyl and phenyl, and most preferably R is a methyl group (herein abbreviated as Me) .
  • R 1 is hydrogen or an organyl group, wherein the organyl group is as defined as in the definition of R above.
  • an organyl group is any organic substituent group, regardless of functional type, having one free valence at a carbon atom.
  • the monosilanes of the general formula (I) formed in the process of the present invention are selected from the group consisting of: RSiH 2 CI, R2SiHCI, RSiHC , more preferably from R 2 SiHCI and RSiHCb, with R as defined above, preferably methyl, vinyl and phenyl, most preferred methyl.
  • the monosilanes of the general formula (I) formed in the process of the present invention are selected from the group consisting of: MeSiH 2 CI, Me 2 SiHCI, MeSiHCb, more preferably from Me 2 SiHCI and MeSiHCb.
  • the monosilanes of the general formula (I I), the disilanes of the general formula (I I I) and the carbodisilanes of the general formula (IV) can be part of any substrate mixture comprising one or more of the silanes of the general formulae (II), (I I I) or (IV).
  • the silane substrate mixture to be reacted preferably comprises greater than about 50 weight-% of silanes of the general formulae (I I), (I I I) or (IV) , more preferably greater than about 75 weight-% of silanes of the general formulae (I I), (I I I) or (IV) , and even more preferably greater than about 90 weight-% of silanes of the general formulae (II), (I I I) and (IV) based on the total weight of the silane substrate mixture to be reacted.
  • the term "subjecting to a reaction” refers to any way of combining the silanes of the general formulae (I I) and (II I) or (IV) and one or more compounds (C) in order to perform a reaction of the silane substrate mixture leading to the formation of products of the general formula (I) , preferably in an open or closed reaction vessel, wherein the reaction may be performed in continuous or batch-wise manner.
  • the products of the general formula (I) are formed in particular by redistribution reactions involving silanes of the general formula (I I) and silanes of the general formulae (I II) and/or (IV) catalyzed by one or more compounds (C).
  • the products of the general formula (I) can also be obtained by a combination of a cleavage reaction of disilanes or carbodisilanes leading to monosilanes of the general formula (I I) followed by redistribution reactions, or redistribution reactions involving the silanes of the general formulae (II I) and (IV) and subsequent cleavage reactions. Both redistribution reactions and cleavage reactions are effected by one or more of the compounds (C) , and all of the mentioned reactions take place in step A).
  • cleavage reaction in accordance with the present invention refers to any kind of reaction in which the Si-Si bond of disilanes of the general formula (I I I) is cleaved, and to any kind of reaction in which one or both of the Si-CH 2 bonds in carbodisilanes of the general formula (IV) is cleaved.
  • the term "redistribution reaction” describes the redistribution of hydrogen, chlorine substituents and/or organyl groups, preferably of hydrogen and chlorine substituents, bound to silicon atoms of one or more silane compounds comprised in the reaction mixture by exchange of these substituents.
  • the exchange can be monitored in particular by 29 Si NMR, by GC and/or GC/MS.
  • the redistribution reactions are catalyzed by the compounds (C).
  • the redistribution reaction of silanes in the context of the present invention includes in particular the comproportionation of two different methylsilanes (one having only chlorine as additional substituents, and one having only hydrogen as additional substituents) with the formation of one specific chlorohydridomethylsilane, such as e.g.
  • silanes selected from the silanes of the general formulae (I I), (I II) and (IV) bearing only chlorine substituents at the silicon atoms and silanes of the general formulae (I I), (I I I) and (IV) bearing only hydrogen substituents at the silicon atoms are reacted.
  • the monosilanes represented by the general formula (II) are MeSiCI 3 , Me 2 SiCI 2 , MeSiH 3 and Me 2 SiH 2 .
  • Preferred disilanes of the general formula (I I I) for the production of silanes of the general empirical formula (I) are Si 2 R 2 CI 4 , Si 2 R 3 CI 3 and Si 2 R 4 CI 2 , or Si 2 R 2 H 4 , Si 2 R 3 H 3 and Si 2 R 4 H 2 , wherein R is as defined above. More preferably, R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, even more preferably from phenyl, vinyl and methyl groups.
  • Particularly preferred disilanes of the general empirical formula (I I I) for the reaction leading to silanes of the general formula (I) are Si 2 Me 2 CI 4 , Si 2 Me 3 CI 3 , Si 2 Me 4 CI 2 and Si 2 Me 2 H 4 , Si 2 Me 3 H 3 , Si 2 Me 4 H 2 .
  • Preferred carbodisilanes of the general formula (IV) for the reaction leading to silanes of the general formula (I) are RCI 2 Si-CH 2 -SiCI 2 R, R 2 CISi-CH 2 -SiCI 2 R, R 2 CISi-CH 2 -SiCIR 2 , R 3 Si-CH 2 - SiCI 2 R and R 3 Si-CH 2 -SiCIR 2 , wherein R is as defined above. More preferably, R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, even more preferably from phenyl, vinyl and methyl groups.
  • carbodisilanes of the general formula (IV) for the reaction leading to silanes of the general formula (I) are RH 2 Si-CH 2 -SiH 2 R, R 2 HSi-CH 2 -SiH 2 R, R 2 HSi-CH 2 -SiHR 2 , R 3 Si- CH 2 -SiH 2 R and R 3 Si-CH 2 -SiHR 2 , wherein R is as defined above. More preferably, R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, even more preferably from phenyl, vinyl and methyl groups.
  • the carbodisilanes of the general formula (IV) are either cleaved in the reactions leading to monosilanes of the general formula (I), or they act as hydrogen or chloride donors in redistribution reactions without being cleaved.
  • carbodisilanes due to their generally higher stability towards cleavage in comparison to disilanes with comparable substitution patterns at the silicon atoms, carbodisilanes can at least partially be reused after reacting in redistribution reactions according to the invention.
  • carbodisilanes of the general formula (IV) partially or fully chlorinated obtained by the redistribution with chlorinated mono- or disilanes of the general formulae (I I) and optionally (I I I) can be regenerated to carbodisilanes of the general formula (IV) with a higher hydrogen content than before by redistribution with fully or mostly hydrogen-substituted organomonosilanes and organodisilanes of the general formulae (I I) and/or (I I I).
  • carbodisilanes of the general formula (IV) partially or fully hydrogenated obtained by the redistribution with hydrogenated mono- or disilanes of the general formulae (II) and optionally (III) can be regenerated to carbodisilanes of the general formula (IV) with a higher chlorine content than before by redistribution with fully or mostly chlorine-substituted organomonosilanes and organodisilanes of the general formulae (II) and/or (III).
  • carbodisilanes of the general formula (IV) for the reactions leading to compounds of the general formula (I) are MeCI 2 Si-CH 2 -SiCI 2 Me, Me 2 CISi-CH 2 -SiCI 2 Me, Me 2 CISi-CH 2 -SiCIMe 2 and MeH 2 Si-CH 2 -SiH 2 Me, Me 2 HSi-CH 2 -SiH 2 Me, Me 2 HSi-CH 2 -SiHMe 2 .
  • the disilanes and carbodisilanes of the general formulae (III) and (IV) are contained in the Direct Process Residue (DPR), or can be derived from precursors present in the Direct Process Residue by partial or full hydrogenation.
  • DPR Direct Process Residue
  • the Direct Process Residue (as received as a side-product of the Direct Process) comprising disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) is submitted to step A).
  • DPR Direct Process Residue
  • the primary current commercial method to prepare alkylhalosilanes and arylhalosilanes is through the Rochow-Muller Direct Process (also called Direct Synthesis or Direct Reaction), in which copper-activated silicon is reacted with the corresponding organohalide, in particular methyl chloride, in a gas-solid or slurry-phase reactor. Gaseous products and unreacted organohalide, along with fine particulates, are continuously removed from the reactor. Hot effluent exiting from the reactor comprises a mixture of copper, metal halides, silicon, silicides, carbon, gaseous organohalide, organohalosilanes, organohalodisilanes, carbosilanes and hydrocarbons.
  • this mixture is first subjected to gas-solid separation in cyclones and filters. Then the gaseous mixture and ultrafine solids are condensed in a settler or slurry tank from which the organohalide, organohalosilanes, hydrocarbons and a portion of organohalodisilanes and carbosilanes are evaporated and sent to fractional distillation to recover the organohalosilane monomers.
  • the solids accumulated in the settler along with the less volatile silicon-containing compounds are purged periodically and sent to waste disposal or to secondary treatment. Organohalodisilanes and carbosilanes left in the post-distillation residues are also fed to hydrochlorination.
  • DPR Direct Process Residue
  • silanes of the general formula (III) and (IV), as received from hydrogenation of the DPR are submitted to step A).
  • hydrogenation of the DPR refers to any reaction in which chlorine substituents of silanes of the DPR are exchanged by hydrogen substituents.
  • the resulting product is referred to as "hydrogenated DPR”.
  • the DPR may be partially or fully hydrogenated, wherein the term fully hydrogenated means that all chlorine substituents at the silicon atoms are exchanged for hydrogen substituents.
  • Hydrogenation is carried out with a hydride donor, selected from the group of metal hydrides, preferably complex metal hydrides such as LiAIH 4 , n-Bu 3 SnH, NaBH 4 , ( -Bu2AIH) 2 or sodium bis(2-methoxyethoxy)aluminumhydride, which is commercially available under the trademarks Vitride® or Red-AI®, for instance, or binary metal hydrides, in particular sodium hydride, lithium hydride or combinations thereof, most preferably lithium hydride.
  • a hydride donor selected from the group of metal hydrides, preferably complex metal hydrides such as LiAIH 4 , n-Bu 3 SnH, NaBH 4 , ( -Bu2AIH) 2 or sodium bis(2-methoxyethoxy)aluminumhydride, which is commercially available under the trademarks Vitride® or Red-AI®, for instance, or binary metal hydrides, in particular sodium hydride, lithium hydride or combinations thereof, most
  • a hydride donor is any compound being capable of providing hydride anions for the Si-CI/Si-H exchange in silanes of the formulae (II), (III) and (IV).
  • metal hydride refers to any hydride donor containing at least one metal atom or metal ion, and preferably includes complex metal hydrides, organometallic reagents and binary metal hydrides.
  • complex metal hydrides refers to metal salts wherein the anions contain hydrides. Typically, complex metal hydrides contain more than one type of metal or metalloid.
  • metal comprises the elements boron, silicon, germanium, arsenic, antimony, tellurium, carbon, aluminum, selenium, polonium, and astatine.
  • the silanes of the general formula (II) are submitted to the reaction conditions in step A) as single or specific compounds represented by general formula (II), or as a mixture of single or specific compounds represented by general formula (II), or as one or more mixtures comprising one or more single or specific compounds represented by general formula (II). More preferably, single compounds represented by the general formula (II) are submitted to the reaction conditions in step A).
  • single compound or “specific compound” in the sense of the present invention means that an isolated compound of at least 90 % purity (purity by weight) is submitted to the reaction of step A).
  • R 1 is hydrogen or an organyl group and can be the same or different.
  • R 1 is preferably an aromatic or aliphatic hydrocarbon group, more preferably R 1 is an alkyl group, even more preferably R 1 is a n-alkyl group, and most preferably the compound of the general formula R 1 4 PCI is n-Bu 4 PCI.
  • R 1 is selected from hydrogen and an organyl group and can be the same or different, more preferably R 1 is an alkyl, cycloalkyl or aryl group, most preferably the organophosphine is PPh3 or n-Bu3P.
  • R 1 in PR 1 3, preferably comprises at least one organyl group.
  • R 1 is selected from hydrogen and an organyl group, preferably an organyl group, more preferably R 1 is an alkyl group, and most preferably the triorganoamine is n-Bu 3 N or NPh 3 .
  • Preferred compounds (C) selected from N-heterocyclic amines are methylimidazoles such as 2-methylimidazole, 4-methylimidazole and 1-methylimidazole, most preferably 2- methylimidazole.
  • R 1 is an organyl group and can be the same or different, more preferably R 1 is an alkyl group, and most preferably the quaternary ammonium compound is n-Bu 4 NCI.
  • the optional step of separating the resulting chlorohydridomonosilanes of the general formula (I) refers to any technical means applied to raise the content of one or more methylmonosilanes according to the general formula (I) in a product or reaction mixture, or which results in the separation of one or more single compounds of the formula (I) from a product or reaction mixture obtained in step A) of the process according to the invention.
  • reaction step A) is carried out in a suitably sized reactor made of materials that are resistant to corrosion by chlorides, such as glass or Hastelloy C. Vigorous agitation may be used to disperse or dissolve the compound (C) and the metal hydride in the reaction mixture.
  • chlorides such as glass or Hastelloy C. Vigorous agitation may be used to disperse or dissolve the compound (C) and the metal hydride in the reaction mixture.
  • step A) is carried out in an organic solvent or mixtures thereof, preferably a high-boiling ether compound, more preferably 1 ,4-dioxane, diglyme or tetraglyme, most preferably diglyme.
  • organic solvent refers to any organic compound or mixtures thereof which is in liquid state at room temperature, and which is suitable as a medium for conducting the redistribution reactions of step A) therein.
  • the organic solvent is preferably inert to the compounds (C) according to present invention under reaction conditions.
  • the starting materials of the general formulae (II), (III) and (IV) and the products of the general formula (I) are preferably soluble in the organic solvent or fully miscible with the organic solvent, respectively.
  • the organic solvent is selected from optionally substituted, preferably unsubstituted linear or cyclic aliphatic hydrocarbons, aromatic hydrocarbons or ether compounds, without being limited thereto.
  • ether compound shall mean any organic compound containing an ether group -O- (one or more ether groups are possible), in particular of the formula R 2 -0-R 3 , wherein R 2 and R 3 are independently selected from an organyl group R as defined above.
  • the organyl group R can be selected for example from optionally substituted, preferably unsubstituted, alkyl, aryl, alkenyl, alkynyl, alkaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, cycloaralkyl, cycloaralkenyl, and cycloaralkynyl groups, preferably from alkyl, alkenyl and aryl groups.
  • R 3 and R 2 are substituted or unsubstituted linear or branched alkyl groups or aryl groups, which may have further heteroatoms such as oxygen, nitrogen, or sulfur.
  • R 3 and R 2 can constitute together an optionally substituted alkylene or arylene group, which may have further heteroatoms such as oxygen, nitrogen, or sulfur, as for instance in dioxanes, in particular 1 ,4-dioxane.
  • the ether compounds can be symmetrical or asymmetrical with respect to the substituents at the ether group(s) -0-.
  • ether compound also comprises linear ether compounds in which more than one ether group may be included, forming a di-, tri-, oligo- or polyether compound, wherein R 3 and R 2 constitute organyl groups when they are terminal groups of the compounds, and alkylene or arylene groups when they are internal groups.
  • a terminal group is defined as any group being linked to one oxygen atom which is part of an ether group, while an internal group is defined as any group linked to two oxygen atoms being a constituent of ether groups.
  • Preferred examples of such compounds are dimethoxy ethane, glycol diethers (glymes), in particular diglyme or tetraglyme, without being limited thereto.
  • the term "high-boiling ether compound” is defined as an ether compound according to the above definition with a boiling point at about 1 .01325 bar (standard atmosphere pressure) of preferably at least about 70 °C, more preferably at least about 85 °C, even more preferably at least about 100 °C, and most preferably at least about 120 °C.
  • high-boiling ethers in the present invention is favourable as it facilitates separation of the desired products of the general formula (I) from the reaction mixture containing the solvent and residual starting materials.
  • the products of the general formula (I) in general have lower boiling points than the high-boiling ethers as defined herein.
  • the boiling points of selected representative products of the general formula (I) are 35 °C (Me 2 SiHCI) and 41 °C (MeSiHC ) at atmospheric pressure, while the representative higher-boiling ether compound diglyme has a boiling point of 162 °C at standard atmosphere pressure.
  • Application of higher-boiling ether compounds as solvents allows higher reaction temperatures and allows a more efficient separation of the desired products from the reaction mixture by distillation.
  • step A) is carried out in the presence of one or more hydride donors, preferably one or more metal hydrides, more preferably one or more metal hydrides selected from the group of alkali metal hydrides and alkaline earth metal hydrides, and most preferably lithium hydride.
  • one or more hydride donors preferably one or more metal hydrides, more preferably one or more metal hydrides selected from the group of alkali metal hydrides and alkaline earth metal hydrides, and most preferably lithium hydride.
  • hydride donor refers to any compound which is capable of donating at least one hydride anion in a reaction of any of the silane substrates of the general formulae (I I), (I II) and (IV) leading to a product of the general formula (I).
  • organometallic hydride reagent refers to compounds that contain bonds between carbon and metal atoms, and which are capable of donating at least one hydride anion used in a reaction of substrates of the general formulae (I I), (I II) or (IV) leading to the products of the general formula (I).
  • Binary metal hydrides in accordance with the present invention are metal hydrides consisting of ions of one specific metal and hydride ions exclusively.
  • the metal hydrides according to the invention are selected from binary metal hydrides, more preferably selected from alkali metal hydrides and earth alkaline metal hydrides, even more preferably selected from the group of lithium hydride, sodium hydride, potassium hydride, magnesium hydride, calcium hydride, even more preferably from lithium hydride and sodium hydride, most preferably the metal hydride is lithium hydride.
  • R is an alkyl or cycloalkyl group, preferably a methyl group.
  • R is an alkyl or cycloalkyl group, more preferably an alkyl or cycloalkyl group having about 1 to about 20 carbon atoms, even more preferably an alkyl or cycloalkyl group having about 1 to about 10 carbon atoms, even further preferably about 1 to about 6 carbon atoms, and most preferably R is a methyl group.
  • the silanes submitted to the reaction comprise one or more silanes selected from the group of
  • the silanes do not have hydrogen substituents.
  • c 0, greater than about 50% of the number of substituents at the silicon atoms of the silanes of the general formulae (II I) and/or (IV) submitted to step A) other than R are chlorine substituents, more preferably greater than about 75% of the number of substituents are chlorine substituents, and most preferably greater than about 90% of the number of substituents other than R at the silicon atoms of the silanes of the general formulae (I II) and (V) submitted to step A) are chlorine substituents.
  • c 0, greater than about 50 mol-% of the silanes of the general formulae (III) and (IV) submitted to step A) do not have hydrogen substituents at the silicon atoms, more preferably greater than about 70 mol-% do not have hydrogen substituents at the silicon atoms, even further preferably, greater than about 90 mol-% do not have hydrogen substituents at the silicon atoms, and most preferably greater than about 95 mol-% of the silanes of the general formulae (II I) and (IV) submitted to step A) do not have hydrogen substituents at the silicon atoms.
  • n silanes of the general formulae (III) and (IV) not having hydrogen substituents at the silicon atoms to silanes of the general formulae (III) and (IV)
  • n silanes of the general formulae (III) and (IV) not having hydrogen substituents at the silicon atoms
  • n silanes of the general formulae (III) and (IV) not having hydrogen substituents at the silicon atoms
  • the silanes of the general formulae (III) and (IV) are obtained from the Direct Process Residue and greater than about 80% of the number of substituents of the silanes of the general formulae (III) and (IV) at the silicon atoms are chlorine substituents, or the monosilanes of the general formula (I I) are submitted to step A) with Direct Process Residue comprising silanes of the general formulae (I II) or (IV) as obtained as side-product from the Direct Process.
  • b 0, greater than about 50% of the number of substituents at the silicon atoms of the silanes of the general formulae (III) and (IV) submitted to step A) other than R are hydrogen substituents, more preferably greater than about 75% of the number of substituents are hydrogen substituents, and most preferably greater than about 90% of the number of substituents other than R at the silicon atoms of the silanes of the general formulae (III) and (V) submitted to step A) are hydrogen substituents.
  • b 0, greater than about 50 mol-% of the silanes of the general formulae (III) and (IV) submitted to step A) do not have chlorine substituents at the silicon atoms, more preferably greater than about 70 mol-% do not have chlorine substituents at the silicon atoms, even further preferably, greater than about 90 mol-% do not have chlorine substituents at the silicon atoms, and most preferably more than about 95 mol-% of the silanes of the general formulae (III) and (IV) submitted to step A) do not have chlorine substituents at the silicon atoms.
  • n silanes of the general formulae (III) and (IV) not having chlorine substituents at the silicon atoms
  • silanes of the general formulae (III) and (IV) are defined as n (silanes of the general formulae (III) and (IV) not having chlorine substituents at the silicon atoms)/ n (silanes of the general formulae (III) and (IV)).
  • the silanes of the general formulae (I I I) and (IV) are derived from the Direct Process Residue by hydrogenation and greater than about 80% of the number of substituents of the silanes of the general formulae (I I I) and (IV) at the silicon atoms are hydrogen substituents, or the monosilanes of the general formula (I I) are submitted to step A) with hydrogenated Direct Process Residue comprising silanes of the general formulae (I I I) or (IV) as obtained by hydrogenation reaction of the side-product from the Direct Process.
  • the monosilanes of the general formula (I I) are R 2 SiH 2 and RSiH 3 , more preferably the monosilanes of the general formula (I I) are R2SiH2 and RSihh, wherein R is selected from vinyl, phenyl and methyl, even more preferably the monosilanes of the general formula (I I) are selected from Me 2 SiH 2 and MeSiH 3 , and most preferably the monosilanes of the general formula (II) are selected from Me 2 SiH 2 and MeSiH 3 , and the silanes of the general formulae (II I) and (IV) are selected from the group of Si 2 Me 2 Cl4, Si 2 Me 3 CI 3 , Si 2 Me 4 CI 2 , (SiCH 2 Si)Me 2 CI 4 , (SiCH 2 Si)Me 3 CI 3 and (SiCH 2 Si)Me 2 CI 4 , and optionally are part of a Direct Process Residue (D
  • the monosilanes of the general formula (I I) are R 2 SiCI 2 and RSiCI 3 , more preferably the monosilanes of the general formula (II) are R 2 SiCI 2 and RSiCI 3 , wherein R is selected from vinyl, phenyl and methyl, even more preferably the monosilanes of the general formula (I I) are selected from Me 2 SiCI 2 and MeSiCI 3 , and most preferably the monosilanes of the general formula (I I) are selected from Me 2 SiCI 2 and MeSiCI 3 , and the silanes of the general formulae (I I I) and (IV) are selected from the group of Si 2 Me 2 H 4 , Si 2 Me 3 H 3 , Si 2 Me H 2 , (SiCH 2 Si)Me 2 H 4 , (SiCH 2 Si)Me 3 H 3 and (SiCH 2 Si)Me 2 H 4 , and optionally are part of a hydrogenation product of the Direct Process Residue (
  • silane substrates of the general formulae (II) , (I I I) or (IV) having one or more hydrogen substituents at the silicon atom(s) in step A) are prepared by a hydrogenation reaction prior to step A).
  • silane substrates of the general formulae (II), (III) or (IV) having one or more hydrogen substituents at the silicon atom(s) in step A) may be prepared by a hydrogenation step prior to step A), or only a part of the silane substrates of the general formulae (II), (III) or (IV) having one or more hydrogen substituents at the silicon atom(s) in step A) may be prepared by a hydrogenation reaction prior to step A).
  • atom(s) shall be understood in the way that above- given description of the preferred embodiment applies to the sole silicon atom in monosilanes of the general formula (II), and to at least one of the silicon atoms in silanes of the general formulae (III) and (IV).
  • hydrogenation refers to the exchange of one or more chlorine substituents at silicon atoms by the same number of hydrogen substituents.
  • the hydrogenation reactions prior to step A) leading to hydrogenated silane substrates of the general formulae (II), (I II) and (IV) are performed with a hydride donor selected from the group of metal hydrides, preferably complex metal hydrides and organometallic hydride reagents such as LiAIH 4 , n-Bu 3 SnH, NaBH 4 , /-Bu 2 AIH or sodium bis(2-methoxyethoxy) aluminum hydride.
  • a hydride donor selected from the group of metal hydrides, preferably complex metal hydrides and organometallic hydride reagents such as LiAIH 4 , n-Bu 3 SnH, NaBH 4 , /-Bu 2 AIH or sodium bis(2-methoxyethoxy) aluminum hydride.
  • the amount of the metal hydride in step A) in relation to the silane substrate compounds to be hydrogenated is in the range of about 0.05 mol-% to about 395.95 mol-%, preferably about 20 mol-% to about 200 mol-%, more preferably about 50 mol-% to about 150 mol-%, and most preferably about 80 mol-% to about 100 mol-%.
  • the molar ratio in % is defined as
  • the compounds selected from monosilanes of the general formula (II), disilanes of the general formula (III) and carbodisilanes of the general formula (IV) are considered, regardless if they are submitted as a part of a mixture comprising other compounds, in particular monosilanes, disilanes and carbodisilanes, which do not fall under the general formulae (II), (III) or (IV), respectively.
  • the amount of the one or more compounds (C) in step A) in relation to the silane substrate compounds is in the range of about 0.0001 mol-% to about 600 mol-%, more preferably about 0.01 mol-% to about 20 mol-%, even more preferably about 0.05 mol-% to about 2 mol-%, and most preferably about 0.05 mol-% to about 1 mol-%.
  • the molar ratio in % is defined as [n (compound or compounds (C) in step A)) / n (silane substrate compounds of the general formulae (II), (III) and (IV) in step A))] x 100.
  • the weight ratio of the silane substrates to the organic solvent(s) is in the range of about 0.01 to about 100, preferably in the range of about 0.1 to about 10, more preferably about 0.5 to about 4, most preferably about 0.5 to about 1.
  • the weight ratio is defined as m (silane substrate compounds of the general formulae (II), (III) and (IV) in step A)) / m (organic solvents in step A)).
  • the step A) is conducted at a temperature of about 0 °C to about 300 °C, preferably about 20 °C to about 200 °C, more preferably about 80 °C to about 200 °C.
  • the reaction temperature in step A) is the temperature of the reaction mixture, i.e. the temperature measured inside the reaction vessel in which the reaction is conducted.
  • the step A) is conducted at a pressure of about 0.1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
  • the indicated pressure ranges refer to the pressure measured inside the reaction vessel used when conducting reaction step A).
  • the monosilanes of the formula (I) are selected from the group consisting of Me 2 SiHCI, MeSiHC and MeSihbCI.
  • the monosilane of the formula (I) is Me 2 SiHCI and it is produced by submitting Me2SiCl2 to the reaction step A), more preferably the monosilane of the formula (I) is Me 2 SiHCI and it is produced by submitting Me 2 SiCI 2 and one or more silanes of the general formulae (III) or (IV) having no chlorine substituents to the reaction step A), even more preferably the monosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me 2 SiCI 2 and one or more silanes selected from the group of the silanes of empirical formulae Si 2 Me 2 H 4 , Si 2 Me 3 H 3 , Si 2 Me 4 H 2 , (SiCH 2 Si)Me 2 H 4 , (SiCH 2 Si)Me 3 H 3 and (SiCH 2 Si)Me 4 H 2 to the reaction step A), most preferably the monosilane of the formula (I) is Me 2 SiHCI and it is produced by submitting Me2Si
  • the monosilane of the formula (I) is Me 2 SiHCI and it is produced by submitting Me 2 SiH 2 to the reaction step A), more preferably the monosilane of the formula (I) is Me 2 SiHCI and it is produced by submitting Me 2 SiH 2 and one or more silanes of the general formulae (III) or (IV) having no hydrogen substituents to the reaction step A), even more preferably the monosilane of the formula (I) is Me 2 SiHCI and it is produced by submitting Me 2 SiH 2 and one or more silanes selected from the group of the silanes of empirical formulae Si 2 Me 2 CI 4 , Si 2 Me 3 CI 3 , Si 2 Me 4 CI 2 , (SiCH 2 Si)Me 2 CI 4 , (SiCH 2 Si)Me 3 CI 3 and (SiCH 2 Si)Me CI 2 to the reaction step A), most preferably the methylmonosilane of the formula (I) is Me 2 SiHCI and it is
  • the monosilane of the formula (I) is MeSiHCb, and it is produced by submitting MeSiCI 3 to the reaction step A), more preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiCI 3 and one or more silanes of the general formulae (III) or (IV) having no chlorine substituents to the reaction step A), even more preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiC and one or more silanes selected from the group of the silanes of empirical formulae Si 2 Me 2 H 4 , Si 2 Me 3 H 3 , Si 2 Me 4 H 2 , (SiCH 2 Si) Me 2 H 4 , (SiCH 2 Si)Me 3 H 3 and (SiCH 2 Si)Me 4 H 2 to the reaction step A), most preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiCb
  • the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiH 3 to the reaction step A), more preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiH 3 and one or more silanes of the general formulae (III) or (IV) having no hydrogen substituents to the reaction step A), even more preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiH 3 and one or more silanes selected from the group of the silanes of empirical formulae Si 2 Me 2 CI 4 , Si 2 Me 3 CI 3 , Si 2 Me 4 CI 2 , (SiCH 2 Si)Me 2 CI 4 , (SiCH 2 Si)Me 3 CI 3 and (SiCH 2 Si)Me 4 CI 2 to the reaction step A), most preferably the monosilane of the formula (I) is MeSiHCb and it is produced by
  • Me 2 SiCI 2 is selected as a starting material for the production of Me 2 SiHCI in step A), more preferably Me 2 SiCI 2 is selected as a starting material for the production of Me 2 SiHCI in step A) by the reaction with one or more silanes selected from the silanes of empirical formulae Si 2 Me 4 H 2 and (SiCH 2 Si)Me 4 H 2 , most preferably Me 2 SiCI 2 is selected as a starting material for the production of Me 2 SiHCI in step A) by the reaction with Si 2 Me 4 H 2 .
  • MeSiCb is selected as a starting material for the production of MeSiHCI 2 in step A), more preferably MeSiCb is selected as a starting material for the production of MeSiHCb in step A) by the reaction with one or more silanes selected from the group of the silanes of empirical formulae consisting of Si 2 Me 2 H 4 and (SiCH 2 Si) Me 2 H , most preferably MeSiCb is selected as a starting material for the production of MeSiHCb in step A) by the reaction with Si 2 Me 2 H .
  • Me 2 SiH 2 is selected as a starting material for the production of Me 2 SiHCI in step A), more preferably Me 2 SiH 2 is selected as a starting material for the production of Me 2 SiHCI in step A) by the reaction with one or more silanes selected from the silanes of empirical formulae Si 2 Me 4 CI 2 or (SiCH 2 Si)Me 4 CI 2 , most preferably Me 2 SiH 2 is selected as a starting material for the production of Me 2 SiHCI in step A) by reaction with Si 2 Me CI 2 .
  • MeSiH 3 is selected as a starting material for the production of MeSiHCb in step A), more preferably MeSihb is selected as a starting material for the production of MeSiHCb in step A) in the presence of one or more silanes selected from the group of the silanes of empirical formulae Si 2 Me 2 CI and/or (SiCH 2 Si)Me 2 CI , most preferably MeSiH 3 is selected as a starting material for the production of MeSiHCb in step A) by reaction with Si 2 Me 2 CI 4
  • the disilanes and carbodisilanes can act as hydride donors or hydride acceptors in redistribution reactions with monosilanes of the general formula (II), and they can be cleaved to monosilanes of the general formulae (II) and (I) under the reaction conditions of step A) in the presence of the compounds (C).
  • the silanes of the general formulae (III) are selected from the group of MeH 2 Si-SiH 2 Me, MeH 2 Si-SiHMe 2 , Me 2 HSi-SiHMe 2 , MeCI 2 Si-SiCI 2 Me, MeCI 2 Si-SiCIMe 2 and Me 2 CISi-SiCIMe 2 .
  • MeH 2 Si-SiH 2 Me and/or MeH 2 Si-SiHMe 2 is/are selected as a starting material for the production of MeSiHCb in step A), more preferably MeH 2 Si-SiH 2 Me is selected as a starting material for the production of MeSiHCb in step A), even more preferably MeH 2 Si- SiH 2 Me is selected as a starting material for the production of MeSiHCb by the reaction with one or more silanes selected from MeSiCb or (SiCH 2 Si)Me 2 Cl4, most preferably MeH 2 Si- SiH 2 Me is selected as a starting material for the production of MeSiHCb in step A) by the reaction with MeSiCI 3 .
  • Me 2 HSi-Sil-IMe2 and/or MeH 2 Si-SiHMe2 is/are selected as a starting material for the production of Me 2 SiHCI in step A), more preferably Me 2 HSi-SiHMe 2 is selected as a starting material for the production of Me 2 SiHCI in step A), even more preferably Me 2 HSi- SiHMe 2 is selected as a starting material for the production of Me 2 SiHCI by the reaction with one or more silanes selected from Me 2 SiCI 2 and (SiCH 2 Si)Me 4 CI 2 , most preferably Me 2 HSi- SiHMe 2 is selected as a starting material for the production of Me 2 SiHCI in step A) by the reaction with Me 2 SiCI 2 .
  • MeCI 2 Si-SiCI 2 Me and/or MeCI 2 Si-SiCIMe 2 is/are selected as a starting material for the production of MeSiHCI 2 in step A), more preferably MeCI 2 Si-SiCI 2 Me is selected as a starting material for the production of MeSiHCI 2 in step A), even more preferably MeCbSi- SiCI 2 Me is selected as a starting material for the production of MeSiHCb by the reaction with one or more silanes selected from MeSiH 3 and (SiCH 2 Si)Me 2 H 4 , most preferably MeCbSi- SiCI 2 Me is selected as a starting material for the production of MeSiHCb in step A) by the reaction with MeSihb.
  • Me 2 CISi-SiCIMe 2 and/or MeCI 2 Si-SiCIMe 2 is/are selected as a starting material for the production of Me 2 SiHCI in step A), more preferably Me 2 CISi-SiCIMe 2 is selected as a starting material for the production of Me 2 SiHCI in step A), even more preferably Me 2 CISi-SiCIMe 2 is selected as a starting material for the production of Me 2 SiHCI by the reaction with one or more silanes selected from Me 2 SiH 2 and (SiCH 2 Si)Me4H 2 , most preferably Me 2 CISi-SiCIMe 2 is selected as a starting material for the production of Me 2 SiHCI in step A) by the reaction with Me 2 SiH 2 .
  • the carbodisilanes of the general formula (IV) are selected from the group consisting of MeH 2 (SiCH 2 Si)H 2 Me, MeH 2 (SiCH 2 Si)HMe 2 , Me 2 H(SiCH 2 Si)HMe 2 , MeCb(SiCH 2 Si)CI 2 Me, MeCb(SiCH 2 Si)CIMe 2 and Me 2 CI(SiCH 2 Si)CIMe 2 .
  • MeH 2 (SiCH 2 Si)H 2 Me and/or MeH 2 (SiCH 2 Si)HMe 2 is/are selected as a starting material for the production of MeSiHCb in step A), more preferably MeH 2 (SiCH 2 Si)H 2 Me is selected as a starting material for the production of MeSiHCb in step A), even more preferably MeH 2 (SiCH 2 Si)H 2 Me is selected as a starting material for the production of MeSiHCb by the reaction with one or more silanes selected from the silanes of empirical formulae MeSiC and Si 2 Me2CI 4 , most preferably MeH2(SiCH2Si)H 2 Me is selected as a starting material for the production of MeSiHC in step A) by the reaction with MeSiCI 3 .
  • Me2H(SiCH 2 Si)HMe2 and/or MeH2(SiCH 2 Si)HMe2 is/are selected as a starting material for the production of Me 2 SiHCI in step A), more preferably Me2H(SiCH2Si)HMe2 is selected as a starting material for the production of Me2SiHCI in step A), even more preferably Me2H(SiCH2Si)HMe 2 is selected as a starting material for the production of Me 2 SiHCI by the reaction with one or more silanes selected from Me 2 SiCI 2 and Si2Me4Cl2, most preferably Me2H(SiCH2Si)HMe2 is selected as a starting material for the production of Me 2 SiHCI in step A) by the reaction with Me 2 SiCI 2 .
  • MeCI 2 (SiCH 2 Si)CI 2 Me and/or MeCI 2 (SiCH 2 Si)CIMe 2 is/are selected as a starting material for the production of MeSiHC in step A), more preferably MeC CSiChbSrjChMe is selected as a starting material for the production of MeSiHC in step A), even more preferably MeChCSiChbSrjChMe is selected as a starting material for the production of MeSiHC by the reaction with one or more silanes selected from MeSiH 3 and Si2Me 2 H4, most preferably MeChCSiChbSrjChMe is selected as a starting material for the production of MeSiHC in step A) by the reaction with MeSiH 3 .
  • Me 2 CI(SiCH 2 Si)CIMe 2 and/or MeCI 2 (SiCH 2 Si)CIMe 2 is/are selected as a starting material for the production of Me 2 SiHCI in step A), more preferably Me2CI(SiCH2Si)CIMe2 is selected as a starting material for the production of Me2SiHCI in step A), even more preferably Me 2 CI(SiCH2Si)CIMe2 is selected as a starting material for the production of Me2SiHCI by the reaction with one or more silanes selected from Me2SiH2 and Si2Me 4 H2, most preferably Me 2 CI(SiCH2Si)CIMe2 is selected as a starting material for the production of Me 2 SiHCI in step A) by the reaction with Me 2 SiH2.
  • step A) is carried out in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above.
  • R 1 is a hydrogen or an organyl group, as defined above, which can be the same or different, more preferably R 1 is an aromatic group or an aliphatic hydrocarbon group, even more preferably R 1 is an alkyl or cycloalkyl group, even further preferably R 1 is a n-alkyl group, and most preferably the compound of the general formula R 1 4 PCI is n-Bu PCI.
  • a compound (C) of the formula R 1 4 PCI acts as a catalyst for the redistribution reaction in step A), and may also act as a reagent for the cleavage of disilanes and carbodisilanes of the general formulae (III) or (IV).
  • the compounds of formula R 1 4 PCI are formed in situ from compounds of the formulae R 1 3 P and R 1 CI, wherein R 1 is H or an organyl group, preferably R 1 is at least one organyl group, preferably all R 1 are organyl groups.
  • R 1 in R 1 4 PCI formed in situ is H or an organyl group and can be the same or different, and preferably R 1 CI is HCI or a chloroalkane, more preferably the R are the same and R 1 CI is a 1 -chloroalkane with up to about 20 carbon atoms, even more preferably the R 1 are the same and R 1 CI is a 1 -chloroalkane with up to about 10 carbon atoms, and most preferably the R 1 are the same and R 1 CI is 1 -chlorobutane.
  • formed in situ in accordance with the invention means that the compound R 1 4 PCI is formed from R 1 3P and R 1 CI by combination of these compounds in the reaction vessel in which reaction step A) is performed, or by combination of these compounds in a separate reaction vessel prior to step A) and addition of this mixture to reaction step A) without further work-up.
  • step A) is carried out in the presence of at least one compound of the formula (C) , preferably R 1 4 PCI, and lithium hydride.
  • step A) is carried out in the presence of lithium hydride and at least one compound of the formula R 1 4 PCI, wherein R 1 is an organyl group and can be the same or different. More preferably, step A) is carried out as described above, wherein the silane substrates of the general formulae (II), (II I) or (IV) do not have any hydrogen substituents at the silicon atoms. Even more preferably, step A) is carried out as described before, wherein the monosilane of the general formula (I I) submitted to the reaction is selected from the group of Me2SiC and MeSiC .
  • step A) is carried out in the presence of n-Bu 4 PCI.
  • n-Bu PCI was found to be a particularly effective redistribution catalyst, and also an effective reagent for the cleavage of disilanes and carbodisilanes.
  • cleavage of disilanes refers to the cleavage of the Si-Si bond leading to the formation
  • cleavage of carbodisilanes refers to the cleavage of the bonds connecting the silicon atoms to the methylene unit linking the two silicon atoms of the carbodisilanes.
  • step A) is carried out in the presence of n-Bu PCI and in the presence of a high- boiling ether compound, more preferably step A) is carried out in the presence of lithium hydride and a high-boiling ether compound selected from the group of diglyme, tetraglyme and 1 ,4-dioxane and mixtures thereof, most preferably in the presence of a high-boiling ether compound selected from the group of diglyme, tetraglyme and 1 ,4-dioxane, and mixtures thereof and lithium hydride.
  • step A) is carried out in the presence of n-Bu PCI, wherein Me 2 SiCI 2 or MeSiCb is submitted to the reaction step, more preferably step A) is carried out in the presence of n-Bu PCI, wherein Me 2 SiCI 2 or MeSiCb is submitted to the reaction step in the further presence of lithium hydride.
  • step A) is carried out in the presence of n-Bu PCI, wherein the silane substrate submitted to the reaction comprises disilanes of the general formula (III), more preferably disilanes of the general formula (III) not bearing any hydrogen substituents at the silicon atoms, most preferably the disilanes of the general formula (III) are selected from the group of the empirical formulae Si 2 Me 2 CI 4 , Si 2 Me 3 CI 3 and Si 2 Me CI 2 .
  • step A) is carried out in the presence of n-Bu PCI and lithium hydride.
  • the products obtained from step A) carried out in the presence of n-Bu PCI and lithium hydride are selected from the compounds of the general formulae (I) RSiHCb and R 2 SiHCI, wherein R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, more preferably R in RSiHCb and R 2 SiHCI obtained from step A) carried out in the presence of n- Bu 4 PCI and lithium hydride is selected from the group consisting of methyl, vinyl and phenyl groups, and most preferably R is a methyl group.
  • R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, more preferably R in RSiHCb and R 2 SiHCI obtained from step A) carried out in the presence of n- Bu 4 PCI and lithium hydride is selected from the group consisting of methyl, vinyl and phenyl groups, and most preferably R is a methyl group.
  • Me 2 SiHCI is produced in the presence of n-Bu PCI and lithium hydride by the reaction of a monosilane of the general formula (II) with a silane substrate comprising disilanes of the general formula (I II) derived from a Direct Process Residue
  • Me 2 SiHCI is produced in step A) in the presence of n-Bu PCI and lithium hydride by the reaction of a monosilane of the general formula (I I) with a silane substrate comprising disilanes of the general formula (III) derived from a Direct Process Residue bearing no hydrogen atoms at the silicon atoms
  • Me 2 SiHCI is produced in step A) in the presence of n-Bu PCI and lithium hydride by the reaction of Me 2 SiCI 2 with a silane substrate comprising disilanes of the general formula (III) based on the Direct Process Residue bearing no hydrogen atoms at the silicon atoms, and most preferably
  • MeSiHCb is produced in the presence of n-Bu PCI and lithium hydride by the reaction of a monosilane of the general formula (II) with a silane substrate comprising disilanes of the general formula (I II) derived from a Direct Process Residue
  • MeSiHCb is produced in step A) in the presence of n-Bu 4 PCI and lithium hydride by the reaction of a monosilane of the general formula (I I) with a silane substrate comprising disilanes of the general formula (II I) derived from a the Direct Process Residue bearing no hydrogen atoms at the silicon atoms
  • MeSiHC is produced in step A) in the presence of n-Bu PCI and lithium hydride by the reaction of MeSiCb with a silane substrate comprising disilanes of the general formula (III) derived from a Direct Process Residue bearing no hydrogen atoms at the silicon atoms
  • Me2SiHCI is produced by the reaction of Me2SiCb in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above.
  • Me 2 SiHCI is produced by the reaction of Me 2 SiCI 2 with silanes selected from disilanes of the general formula (III) and carbodisilanes of the general formula (IV) having no chlorine substituents at the silicon atoms in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above, more preferably Me2SiHCI is produced by the reaction of Me 2 SiCI 2 with silanes selected from disilanes of the general formula (III) and carbodisilanes of the general formula (IV) having no chlorine substituents at the silicon atoms, wherein the molar ratio of Me 2 SiCI 2 to silanes of the general formulae (I II) and/or (IV) having no chlorine substituents at the silicon atoms is in the range of about 99 to about 1 in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above, even more preferably the molar ratio of Me 2 SiCI 2 to silane
  • Me 2 SiHCI is produced by the reaction of Me 2 SiH 2 in the presence of at least one compound of the formula R 1 PCI, wherein R 1 is as defined above.
  • Me 2 SiHCI is produced by the reaction of Me 2 SiH 2 with silanes selected from disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) having no hydrogen substituents at the silicon atoms in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above, more preferably Me 2 SiHCI is produced by the reaction of Me2SiH2 with silanes selected from disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) having no hydrogen substituents at the silicon atoms, wherein the molar ratio of Me 2 SiH 2 to silanes of the general formulae (III) and/or (IV) having no hydrogen substituents at the silicon atoms is in the range of about 1 to about 99 in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above, even more preferably the molar ratio of Me 2 SiH 2
  • MeSiHC is produced by the reaction of MeSiCb in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above.
  • MeSiHCb is produced by the reaction of MeSiCb with silanes selected from disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) having no chlorine substituents at the silicon atoms in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above, more preferably MeSiHCb is produced by the reaction of MeSiC with silanes selected from disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) having no chlorine substituents at the silicon atoms, wherein the molar ratio of MeSiCb to silanes of the general formulae (III) and/or (IV) having no chlorine substituents at the silicon atoms is in the range of about 99 to about 1 in the presence of at least one compound of the formula R 1 PCI, wherein R 1 is as defined above, even more preferably the molar ratio of MeSiCb to silane
  • MeSiHCb is produced by the reaction of MeSiH 3 in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above.
  • MeSiHC is produced by the reaction of MeSiH 3 with silanes selected from disilanes of the general formula (I I I) and/or carbodisilanes of the general formula (IV) having no hydrogen substituents at the silicon atoms in the presence of at least one compound of the formula R 1 4PCI, wherein R 1 is as defined above, more preferably MeSiHC is produced by the reaction of MeSiH 3 with silanes selected from disilanes of the general formula (I I I) and/or carbodisilanes of the general formula (IV) having no hydrogen substituents at the silicon atoms, wherein the molar ratio of MeSihh to silanes of the general formulae (I I I) and/or (IV) having no hydrogen substituents at the silicon atoms is in the range of about 1 to about 99 in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above, even more preferably the molar ratio of MeS
  • step A) and/or B) can be performed in a continuous or batch-wise manner, preferably both steps A) and B) are performed in a continuous manner.
  • the step of separating the resulting monosilanes of the formula (I) is carried out by distillation and/or condensation.
  • distillation relates to any process for separating components or substances from a liquid mixture by selective evaporation and condensation. Therein, distillation may result in practically complete separation of the constituents of a mixture, thus leading to the isolation of nearly pure compounds, or it may be a partial separation that increases the concentration of selected constituents of the mixture in the distillate when compared to the mixture submitted to distillation.
  • the distillation processes which may constitute separation step B) can be simple distillation, fractional distillation, vacuum distillation, short path distillation or any other kind of distillation known to the skilled person.
  • the step B) of separating the monosilanes of the formula (I) according to the invention can comprise one or more batch distillation steps, or can comprise a continuous distillation process.
  • the term “condensation” may comprise separation or enrichment of one or more compounds of the general formula (I) from the reaction mixture by volatilization from the reaction vessel and condensation as a liquid and/or solid in a refrigerated vessel from which it can be subsequently recovered by distillation, or by solution in an ether solvent.
  • the monosilanes can be absorbed in an ether solvent contained in a refrigerated vessel.
  • the process is performed under inert conditions.
  • the term "performed under inert conditions" means that the process is partially or completely carried out under the exclusion of surrounding air, in particular of moisture and oxygen.
  • surrounding air in particular of moisture and oxygen.
  • closed reaction vessels, reduced pressure and/or inert gases, in particular nitrogen or argon, or combinations of such means may be used.
  • methylmonosilanes of the general formula (I) as defined above are obtained by the process according to any of the previous embodiments.
  • compositions comprising at least one methylmonosilane of the general formula (I) as defined above are obtained by the process according to any of the previous embodiments.
  • R is an organyl group
  • x 1 to 3, preferably 1 to 2,
  • y 1 to 3, preferably 1 to 2,
  • n 0 to 5
  • At least one silane of the formula (II), (III) or (IV) has at least one chlorine substituent at the silicon atom
  • silanes of the formula (II), (III) or (IV) submitted to the reaction is selected from the group consisting of:
  • R 1 is selected from the group consisting of hydrogen and an organyl group, which can be the same or different, more preferably R 1 is selected from the group consisting of an aromatic group and an aliphatic hydrocarbon group, even more preferably a n-alkyl group, and most preferably a n-butyl group,
  • R 1 is selected from the group consisting of hydrogen and an organyl group and can be the same or different, preferably R 3 P, wherein R is as defined above and can be the same or different, such as preferably PPh 3 ,
  • R 1 is selected from the group consisting of hydrogen or an organyl group and can be the same or different, preferably R 3 N, wherein R is as defined above and can be the same or different, such as preferably n-Bu 3 N,
  • methylimidazoles such as 2-methylimidazole, 4- methylimidazole and 1 - methylimidazole, and
  • R 1 4 NCI - ammonium compounds, such as R 1 4 NCI, wherein R 1 is selected from the group consisting of hydrogen and an organyl group and can be the same or different, preferably R 4 NCI, wherein R is as defined above and can be the same or different, such as preferably n- Bu 4 NCI, and
  • step A) optionally a step of separating the resulting monosilanes of the general formula (I). 2.
  • step A) is carried out in the presence of one or more, preferably one organic solvent, preferably an high-boiling ether compound, more preferably 1 ,4-dioxane, diglyme or tetraglyme, most preferably diglyme.
  • organic solvent preferably an high-boiling ether compound, more preferably 1 ,4-dioxane, diglyme or tetraglyme, most preferably diglyme.
  • step A) is carried out in the presence of one or more hydride donors, preferably one or more metal hydrides, more preferably one or more metal hydrides selected from the group of alkali metal hydrides and alkaline earth metal hydrides, and most preferably lithium hydride.
  • one or more hydride donors preferably one or more metal hydrides, more preferably one or more metal hydrides selected from the group of alkali metal hydrides and alkaline earth metal hydrides, and most preferably lithium hydride.
  • R is an alkyl or cycloalkyl group, preferably a methyl group.
  • silanes of the formulae (II), (II I) or (IV) submitted to the reaction comprise one or more silanes selected from the group consisting of
  • silane substrates of the general formulae (II), (III) or (IV) having one or more hydrogen substituents at the silicon atom(s) in step A) are prepared by a hydrogenation reaction prior to step A).
  • step A) in relation to the silane substrate compounds is in the range of about 0.05 mol-% to about 395.95 mol-%, preferably about 20 mol-% to about 200 mol-%, more preferably about 50 mol-% to about 150 mol-%, and most preferably about 80 mol-% to about 100 mol-%.
  • the amount of the one or more compounds (C) in step A) in relation to the silane substrate compounds is in the range of about 0.0001 mol-% to about 600 mol-%, more preferably about 0.01 mol-% to about 20 mol-%, even more preferably about 0.05 mol-% to about 2 mol-%, and most preferably about 0.05 mol-% to about 1 mol-%.
  • step A) is conducted at a temperature of about 0 °C to about 300 °C, preferably about 20 °C to about 250 °C, more preferably about 80 °C to about 220 °C.
  • step A) is conducted at a pressure of about 0.1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
  • silanes of the general formula (II) are selected from the group consisting of Me 2 SiCI 2 , MeSiC , Me 2 SiH2 and MeSih .
  • silanes of the general formulae (III) are selected from the group of MeH 2 Si-SiH 2 Me, MeH 2 Si-SiHMe 2 , Me 2 HSi-SiHMe2, MeC Si-SiC Me, MeCI 2 Si-SiCIMe 2 and Me 2 CISi-SiCIMe 2 .
  • carbodisilanes of the general formula (IV) are selected from the group consisting of MeH 2 (SiCH 2 Si)H 2 Me, MeH 2 (SiCH 2 Si)HMe 2 , Me 2 H(SiCH 2 Si)HMe 2 , MeCI 2 (SiCH 2 Si)CI 2 Me, MeCI 2 (SiCH 2 Si)CIMe 2 and Me 2 CI(SiCH 2 Si)CIMe 2 .
  • step A) is carried out in the presence of at least one compound of the formula R ⁇ PCI, wherein R 1 is as defined above.
  • step A) is carried out in the presence of at least one compound of the formula R ⁇ PCI, wherein R 1 is as defined above.
  • step A) is carried out in the presence of at least one compound of the formula R ⁇ PCI, wherein R 1 is as defined above.
  • step A) is carried out in the presence of at least one compound of the formula R ⁇ PCI, wherein R 1 is as defined above.
  • step A is carried out in the presence of at least one compound of the formula R ⁇ PCI, wherein R 1 is as defined above.
  • step A) is carried out in the presence of at least one compound of the formula R 1 4PCI and lithium hydride.
  • step A) is carried out in the presence of n-Bu PCI.
  • step A) is carried out in the presence of n-Bu PCI and lithium hydride.
  • step A) Me 2 SiHCI is produced by the reaction of Me 2 SiCI 2 in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above.
  • step A) Me 2 SiHCI is produced by the reaction of Me 2 SiH 2 in the presence of at least one compound of the formula R 1 4 PCI, wherein R 1 is as defined above.
  • step A) MeSiHC is produced by the reaction of MeSiC in the presence of at least one compound of the formula R 1 PCI, wherein R 1 is as defined above.
  • step A) MeSiHCb is produced by the reaction of MeSihh in the presence of at least one compound of the formula R 1 PCI, wherein R 1 is as defined above.
  • compositions comprising at least one methylmonosilane of the general formula (I) as defined above, as obtainable by the process according to any of the embodiments 1 to 31 .
  • step A) and/or B) can be performed in a continuous or batch-wise manner, preferably both steps A) and B) are performed in a continuous manner.
  • the metal salts as well as the solvents used were carefully dried according to procedures known from the literature.
  • the reactions investigated were generally performed in sealed NMR tubes first to prevent evaporation of low boiling reaction products, such as hydrogenated organomonosilanes, and to elucidate the reaction conditions (temperature, time) for the performed reactions. Subsequently, these conditions were exemplarily transferred onto cleavage reactions in a preparative scale in a closed system, preferably a sealed glass ampoule to avoid evaporation of low boiling reaction educts and products, e.g. organochloro- and organohydridosilanes. After the reaction was completed, the ampoule was frozen, opened under vacuum and products formed were isolated by combined condensation/distillation procedures. Products were analyzed and characterized by standard procedures, especially by NMR spectroscopy and GC/MS analyses.
  • MehbSi-SihbMe (VIII, 0.8 mmol) and MeSiC (1.3 mmol) were mixed with a catalytic amount of the redistribution catalyst of n-Bu 4 PCI (0.02 mmol) in diglyme (0.35 ml) as solvent in an NMR tube, solidified at -196 °C (liquid nitrogen) and sealed in vacuo. After warming the samples to r.t., 29 Si- and 1 H-NMR spectra were measured to prove the degree of SiH/SiCI redistributions after different reaction times and temperatures to control and quantify product formation by integration of the intensity of relevant NMR signals within the mixture.
  • Example 3 The experiment was conducted in analogy to Example 1 , but in contrast to Example 1 the molar amount of dimethyldisilane VIII was reduced to half of the original amount (0.4 mmol), while methyltrichlorosilane IV was used in excess (1.7 mmol). Disilane cleavage and redistribution started already at r.t. giving nearly equimolar amounts of the target compounds V and VI. With longer reaction times, the relative amount of compound VI was strongly increased by chlorination of methylsilane VII and methylchlorosilane V. At 80 °C, the molar ratio of silanes V/VI was 12.2/68.5, demonstrating targeted product formation by control of the reaction conditions. Increasing the reaction temperature to 120 °C (19 h) supported further redistribution of compounds IV and V to give MeSiHCh VI in 73% yield. The results are displayed in Table 3. Table 3
  • Example 2 In the experiment the same solvent, catalyst and reaction vessel as in Example 1 was used, but the mixture of dimethyltetrachlorodisilane (XIII, 1.1 mmol) and methylsilane (VII, 0.7 mmol) already reacted at r.t. to give a mixture with a complex product distribution: the target compound V was formed in a molar amount of 41 %, with 26% of methyldichlorosilane, and the starting compound VII was already consumed nearly quantitatively (3.4% remaining). After 38 h at room temperature (r.t.), the molar amount of compound V was drastically reduced to 22% while that of dichlorosilane VI was increased to 65%.
  • XIII dimethyltetrachlorodisilane
  • VI methylsilane
  • Tetramethyldichlorodisilane (XV, 1 .1 mmol), Me2SiH2 (I, 0.8 mmol), diglyme (0.35 ml) and n- Bu 4 PCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. The starting materials reacted already at r.t. to give 38.5% of Me 2 SiHCI I II , the relative molar amount of tetramethylchlorohydridodisilane XVI was about 22%.
  • Tetramethyldisilane (XIV, 0.6 mmol), Me 2 SiCI 2 (II, 1 .2 mmol), diglyme (0.35 ml) and n-Bu 4 NCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. After 7 days of reaction time at r.t.
  • the starting disilane was chlorinated to give 2% of disilane XV, methylhydridochlorodisilane XVI was formed in a molar amount of 16.4%; both disilanes were formed by redistribution at the disilane skeleton. Si-Si bond cleavage of tetramethyldisilane XIV and subsequent redistribution of formed Me 2 SiH 2 with chlorosilanes gave compound III in 9.6% yield.
  • Tetramethyldichlorodisilane (XV, 1.1 mmol), methylsilane (VII, 0.8 mmol), diglyme (0.35 ml) and n-Bu 4 PCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to - 196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. Chlorosilane III was not formed at r.t. even after 36 hours, while monosilanes V and VI were produced in a molar amount of about 23% (Table 10).
  • Tetramethyldisilane (XIV, 0.3 mmol), excess MeSiC (IV, 1.7 mmol), diglyme (0.35 ml) and n-Bu 4 PCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. Me 2 SiHCI III was not detected at r.t. but the disilane was chlorinated to give disilane XV (12%).
  • Examples 12 and 13 clearly demonstrate the potential to produce the most valuable methylhydridochlorosilanes starting from formerly isolated raw materials of the Mtiller Rochow Direct Process (monosilanes) and the formerly isolated disilane from the Direct Process Residue (DPR).
  • DPR Direct Process Residue
  • a complex mixture of methylchlorocarbodisilanes (0.5 mmol, carbodisilane distribution is listed in Table 16), Me 2 SiH 2 (I, 1.4 mmol), diglyme (0.35 ml) and n-Bu 4 PCI (0.02 mmol) as redistribution catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. At 80 °C (25 h) dimethylsilane I was chlorinated to form compound III in 52% yield, while the methylchlorocarbodisilanes were hydrogenated.
  • Carbodisilane (HMe 2 Si) 2 CI-l2 (XXVI I I , 0.3 mmol), Me 2 SiCI 2 (I I , 1 .7 mmol) , diglyme (0.35 ml) and n-BmPCI (0.04 mmol) as redistribution catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen) . After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. As displayed in Table 19, Cl/H redistribution at the silicon atom was not observed at r.t.
  • a complex mixture of methylhydridocarbodisilanes (0.2 mmol, carbodisilane distribution in the mixture is listed in Table 21 ), Me 2 SiCI 2 (I I , 1 .5 mmol), diglyme (0.35 ml) and n-Bu 4 PCI (0.05 mmol) as redistribution catalyst were placed in an NMR tube that was cooled to - 196 °C (liquid nitrogen) . After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NM R spectroscopy at different temperatures. Already at r.t.
  • Me 2 CISi-SiCIMe 2 was cleaved as well as partially and fully hydrogenated to give compounds XIV and XVI in 4% and 17% yield.
  • Targeted product Me 2 SiHCI III was formed in 44% yield besides Me 2 SiH 2 in 17% yiled.
  • Prolonged reaction times (+22 h) led to further hydrogenation by LiH to give compound I in 35% yield, while targeted product III was reduced to 42%.
  • the amount of disilanes XV and XVI decreased to 1 % and 5%, respectively, while the amount of the fully hydrogenated disilane XIV increased slightly (6%).
  • Trisilanes were formed in a molar amount of 5% (Table 27).
  • the reaction was performed in an analogous manner to the reaction of Example 24 using MeC Si-SiC Me (0.6 mmol), MeSiC (0.6 mmol), LiH (1.5 mmol), diglyme (0.4 ml) and PPh 3 (0.05 mmol) as redistribution catalyst.

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Abstract

The invention relates to a process for the manufacture of organomonosilanes bearing both hydrogen and chlorine substituents at the silicon atom by subjecting one or more organomonosilanes to the reaction with one or more di- or carbodisilanes in the presence of one or more compounds (C) acting as a redistribution catalyst, wherein at least one of the silanes has only hydrogen and organic residues at the silicon atoms.

Description

Process for the production of organohydridochlorosilanes from hydridosi lanes
TECHNICAL FIELD
The present invention relates to the production of hydridosilanes, in particular to the production of hydridochlorosilanes, in particular of mono- and dichlorohydridosilanes in particular, methylchlorohydridomonosilanes selected from Me2Si(H)CI, MeSi(H)CI2, and MeSi(H)2CI.. More specifically, the invention relates to a process for the production of hydridochlorosilanes starting from hydridosilanes.
BACKGROUND OF THE INVENTION
Organohydridosilanes are useful starting materials in synthetic organosilicon chemistry, and therefore constitute an industrially valuable class of compounds. Such organosilanes bearing both chloro- and hydrido substituents constitute attractive starting materials in synthesis due to their bifunctional nature, which means they have functional groups of different reactivities. The chloride substituent is a better leaving group than the hydride group and allows, for instance, the controlled addition of further monomeric or oligomeric siloxane units with retention of the Si-H bond under mild conditions, thereby rendering said chlorohydridosilanes useful as blocking and coupling agents in the synthesis of defined oligo- and polysiloxanes.
Such compounds generally find a wide range of applications, for instance for the manufacture of adhesives, sealants, mouldings, composites and resins for example in the fields of electronics, automotive, construction and many more.
US 2013/172593A1 and US 2013/172594A1 relate to a catalytic process for producing an organohalosilane monomer composition from a high-boiling residue. In such process no hydridoorganylsilanes (with no chlorine substituent) are reacted.
US 2012/1 14544 A1 relates to organic chlorohydrosilanes, which is prepared by reacting a dichlorosilane with a trichlorosilane in the presence of a quaternary organic phosphonium salt catalyst. Also in such process no hydridoorganylsilanes (with no chlorine substituent) are reacted.
JP H03 24091 A relates to a process of manufacturing R2SiHCI from R2SiCI2. Also in such process no hydridoorganylsilanes (with no chlorine substituent) are reacted.
The Si-H moieties present in hydridochlorosilanes can be utilized for post-synthesis modifications and functionalisations, for instance for the introduction of organic residues to polyorganosiloxanes or for cross-linking by hydrosilylation reactions, which is desirable in various kinds of compositions containing polyorganosiloxanes. Synthesis of functionalized polysiloxanes starting with transformations via the Si-H bond(s) followed by hydrolysis or alcoholysis of the Si-CI bond(s) and optionally condensation for the formation of polysiloxanes is also viable.
Although there is a high demand for such bifunctional silanes having both Si-H and Si-CI bonds, there is no conventional, economically reasonable and sustainable industrial process for the synthesis of such building blocks disclosed yet. In particular for the chlorohydridosilanes MeSiHC and Me2SiHCI, there is a strong need for such a production process.
Many procedures for the production of chlorosilanes containing both Si-H and Si-CI bonds are based on organohydridosilanes serving as starting materials. The preparation of organosilicon hydrides and organosilicon compounds containing both Si-H and Si-CI bonds from organosilicon halides, in particular, organosilicon chlorides, is also known in the art.
PROBLEM TO BE SOLVED
The problem to be solved by the present invention is the provision of a process for the production of in particular mono- and dichlorohydridoorganosilanes from in particular hydridosilanes. In particular, it is an object of present invention to provide a new process with improved performance over the conventional methods regarding yield of the reaction, purity of products, selectivity of the conversion, convenience of the reaction procedure, convenience of the work-up procedure, easy handling of the reagents and cost efficiency of the process.
According to the present invention this problem is solved as follows.
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for the manufacture of monosilanes of the general formula (I):
RxSlHyClz (I),
wherein R is an organyl group,
x = 1 to 3, preferably 1 to 2,
y = 1 to 3, preferably 1 to 2, z = 0 to 3, preferably 1 to 2, and
x + y + z = 4,
comprising: A) the step of subjecting one or more monosilanes of the general formula (II) RaSiHbCIc (II) wherein R is as defined above,
a = 1 to 3,
b = 0 to 3,
c = 0 to 3 and
a + b + c = 4, and to a reaction with one or more silanes selected from the group of a) disilanes of the general empirical formula (III)
ReSi2HfClg (III) wherein R is as defined above,
e = 1 to 5,
f = 0 to 5,
g = 0 to 5 and
e + f + g = 6,
and
b) carbodisilanes of the general empirical formula (IV) Rm(SiCH2Si)HnClo (IV)
wherein R is as defined above,
m = 1 to 5,
n = 0 to 5,
o = 0 to 5 and
m + n + o = 6
with the proviso that at least one silane of the formula (II), (III) or (IV) has at least one chlorine substituent at the silicon atom,
and wherein at least one of the silanes of the formula (II), (III) or (IV) submitted to the reaction is selected from the group consisting of:
a monosilane of the general formula (II) with c = 0,
a disilane of the general formula (III) with g = 0, and
a carbodisilane of the general formula (IV) with o = 0,
in the presence of one or more compounds (C) selected from the group of:
- R14PCI, wherein R1 is hydrogen or an organyl group, which can be the same or different, preferably R1 is R as defined above, more preferably an aromatic group or aliphatic hydrocarbon group, even more preferably a n-alkyl group, and most preferably a n-butyl group,
- phosphines R1 3P, wherein R1 is hydrogen or an organyl group and can be the same or different, preferably R3P, wherein R is as defined above and can be the same or different, such as preferably PPh3,
- amines R1 3N, wherein R1 is hydrogen or an organyl group and can be the same or different, preferably R3N, wherein R is as defined above and can be the same or different, such as preferably n-Bu3N,
- N-heterocyclic amines, preferably methylimidazoles, such as 2-methylimidazole, 4- methylimidazole and 1- methylimidazole, and
- ammonium compounds, such as R1 4NCI, wherein R1 is hydrogen or an organyl group and can be the same or different, preferably R4NCI, wherein R is as defined above and can be the same or different, such as preferably n-Bu4NCI, B) optionally a step of separating the resulting monosilanes of the general formula (I) from the reaction mixture.
The disilanes of the general empirical formula (III)
ReSi2HfClg (III)
can be depicted also by the structural formula:
R' R'
\ /
R'— Si— Si— R'
/ \
R' R' wherein the substituents R' are independently selected from organyl substituent (R) as defined according to the invention, hydrogen (H) and chlorine (CI), wherein the number of organic substituents e = 1 to 5, the number of hydrogen atoms f = 0 to 5 and the number of chlorine atoms g = 0 to 5, and the total of e + f + g = 6.
The carbodisilanes of the general empirical formula (IV)
Rm(SiCH2Si)HnClo (IV)
can be depicted also by the structural formula:
R" R"
\
R«— si— C H2— -Si— R"
\
R" R" wherein the substituents R" are independently selected from organyl substituents (R) as defined according to the invention, hydrogen (H) and chlorine (CI), and
wherein the number of organic substituents m = 1 to 5, the number of hydrogen atoms n = 0 to 5, the number of chlorine atoms o = 0 to 5, and m + n + o = 6.
In the entire application the meaning of the term "empirical formula" intends to mean that the formulae do not represent the structural formulae, but just sum up the chemical groups or atoms present in the molecule. For example the empirical formula R2S12CI4 may comprise the structural formulae: CI CI CI CI
\ / \ /
R I-— Si— Si— CI R— Si— Si— R
/ \ / \
R CI CI CI
and
The proviso "wherein at least one of the silanes of the formula (II), (III) or (IV) submitted to the reaction is selected from the group consisting of:
a monosilane of the general formula (II) with c = 0,
a disilane of the general formula (III) with g = 0, and
a carbodisilane of the general formula (IV) with o = 0" has the following implications:
Formula RaSiHbClc (II) becomes RaSiHb. Since a = 1 to 3 b must be 1 to 3, that is, the case c = 0 corresponds to a organohydridosilane.
Formula ReSi2HfClg (III) becomes ReSi2Hf. Since e = 1 to 5, f must also 1 to 5, that is, the case g=0 corresponds to a organohydridodisilane.
Formula Rm(SiCH2Si)HnClo (IV) becomes Rm(SiCH2Si)Hn. Since m = 1 to 5, n must be also 1 to 5. That is, the case o = 0 corresponds to organahydridocarbodisilanes.
Accordingly, the process of the present invention requires the use of at least one organohydridosilane (with no chlorine substitution) as starting material.
It will be understood that any numerical range recited herein includes all sub-ranges within that range and any combination of the various endpoints of such ranges or sub-ranges, be it described in the examples or anywhere else in the specification.
It will also be understood herein that any of the components of the invention herein as they are described by any specific genus or species detailed in the examples section of the specification, can be used in one embodiment to define an alternative respective definition of any endpoint of a range elsewhere described in the specification with regard to that component, and can thus, in one non-limiting embodiment, be used to supplant such a range endpoint, elsewhere described.
It will be further understood that any compound, material or substance which is expressly or implicitly disclosed in the specification and/or recited in a claim as belonging to a group of structurally, compositionally and/or functionally related compounds, materials or substances includes individual representatives of the group and all combinations thereof. While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art may envision many other possible variations that are within the scope and spirit of the invention as defined by the claims appended hereto.
In the process of the present invention, preferably one compound of the general formula (I) or a mixture of more than one compound of general formula (I) is formed.
Preferably, the substituent R represents an organyl group, which is bound to the silicon atom via a carbon atom, and which organyl group can be the same or different. Preferably the organyl group is an optionally substituted, more preferably unsubstituted group, which is selected from the groups consisting of: alkyl, aryl, alkenyl, alkynyl, alkaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, cycloaralkyl, cycloaralkenyl, and cycloaralkynyl, even more preferably selected from alkyl, cycloalkyl, alkenyl and aryl, even further preferred selected from methyl, vinyl and phenyl, and most preferably R is a methyl group (herein abbreviated as Me) .
R1 is hydrogen or an organyl group, wherein the organyl group is as defined as in the definition of R above.
According to the present invention, an organyl group is any organic substituent group, regardless of functional type, having one free valence at a carbon atom.
Preferably, the monosilanes of the general formula (I) formed in the process of the present invention are selected from the group consisting of: RSiH2CI, R2SiHCI, RSiHC , more preferably from R2SiHCI and RSiHCb, with R as defined above, preferably methyl, vinyl and phenyl, most preferred methyl.
Further preferably, the monosilanes of the general formula (I) formed in the process of the present invention are selected from the group consisting of: MeSiH2CI, Me2SiHCI, MeSiHCb, more preferably from Me2SiHCI and MeSiHCb.
In an embodiment of the present invention, the monosilanes of the general formula (I I), the disilanes of the general formula (I I I) and the carbodisilanes of the general formula (IV) can be part of any substrate mixture comprising one or more of the silanes of the general formulae (II), (I I I) or (IV). Herein, the silane substrate mixture to be reacted preferably comprises greater than about 50 weight-% of silanes of the general formulae (I I), (I I I) or (IV) , more preferably greater than about 75 weight-% of silanes of the general formulae (I I), (I I I) or (IV) , and even more preferably greater than about 90 weight-% of silanes of the general formulae (II), (I I I) and (IV) based on the total weight of the silane substrate mixture to be reacted. According to the present invention, the term "subjecting to a reaction" refers to any way of combining the silanes of the general formulae (I I) and (II I) or (IV) and one or more compounds (C) in order to perform a reaction of the silane substrate mixture leading to the formation of products of the general formula (I) , preferably in an open or closed reaction vessel, wherein the reaction may be performed in continuous or batch-wise manner.
Herein, the products of the general formula (I) are formed in particular by redistribution reactions involving silanes of the general formula (I I) and silanes of the general formulae (I II) and/or (IV) catalyzed by one or more compounds (C). Furthermore, the products of the general formula (I) can also be obtained by a combination of a cleavage reaction of disilanes or carbodisilanes leading to monosilanes of the general formula (I I) followed by redistribution reactions, or redistribution reactions involving the silanes of the general formulae (II I) and (IV) and subsequent cleavage reactions. Both redistribution reactions and cleavage reactions are effected by one or more of the compounds (C) , and all of the mentioned reactions take place in step A).
The term "cleavage" reaction in accordance with the present invention refers to any kind of reaction in which the Si-Si bond of disilanes of the general formula (I I I) is cleaved, and to any kind of reaction in which one or both of the Si-CH2 bonds in carbodisilanes of the general formula (IV) is cleaved.
According to the present invention, the term "redistribution reaction" describes the redistribution of hydrogen, chlorine substituents and/or organyl groups, preferably of hydrogen and chlorine substituents, bound to silicon atoms of one or more silane compounds comprised in the reaction mixture by exchange of these substituents. The exchange can be monitored in particular by 29Si NMR, by GC and/or GC/MS. The redistribution reactions are catalyzed by the compounds (C).
The redistribution reaction of silanes in the context of the present invention includes in particular the comproportionation of two different methylsilanes (one having only chlorine as additional substituents, and one having only hydrogen as additional substituents) with the formation of one specific chlorohydridomethylsilane, such as e.g.
Me2SiCI2 + Me2SiH2 => 2 Me2SiHCI
2 MeSiCb + MeSihh => 3 MeSiHCI2
opposite to the undesired disproportionation where a chlorohydridomethylsilane react to form two different methylsilanes (one having only chlorine as additional substituents, and one having only hydrogen as additional substituents):
2 Me2SiHCI => Me2SiCI2 + Me2SiH2
3 MeSiHC => 2 MeSiCb + MeSihh. In a preferred embodiment of the process of the invention silanes selected from the silanes of the general formulae (I I), (I II) and (IV) bearing only chlorine substituents at the silicon atoms and silanes of the general formulae (I I), (I I I) and (IV) bearing only hydrogen substituents at the silicon atoms are reacted. That is, for example, monosilanes of the general formulae (I I), wherein c=0, are reacted with disilanes of the general formulae (I I I) , and/or carbodisilanes of the general formulae (IV) , wherein f=n=0, or vice versa, for example, monosilanes of the general formulae (I I), wherein b=0, are reacted with disilanes of the general formulae (I I I), and/or carbodisilanes of the general formulae (IV), wherein g=o=0 are reacted to obtain silanes of the general formula (I) bearing both hydrogen and chlorine substituents at the silicon atoms.
Preferably, the monosilanes subjected to the reaction of the process are represented by the general formula (I I), wherein a is 1 or 2. More preferably, the monosilanes are represented by the general formula (I I) with a = 1 or 2, wherein b = 0. Even more preferably, the monosilanes are represented by the general formula (I I) with a = 1 or 2, b = 0 and R is methyl, vinyl or phenyl.
Also preferably, the monosilanes subjected to the reaction of the process are represented by the general formula (I I) , wherein a is 1 or 2 and c = 0. More preferably, the monosilanes are represented by the general formula (I I) with a = 1 or 2, c = 0 and R is methyl, vinyl or phenyl.
Most preferably, the monosilanes represented by the general formula (II) are MeSiCI3, Me2SiCI2, MeSiH3 and Me2SiH2.
Preferred disilanes of the general formula (I I I) for the production of silanes of the general empirical formula (I) are Si2R2CI4, Si2R3CI3 and Si2R4CI2, or Si2R2H4, Si2R3H3 and Si2R4H2, wherein R is as defined above. More preferably, R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, even more preferably from phenyl, vinyl and methyl groups.
Particularly preferred disilanes of the general empirical formula (I I I) for the reaction leading to silanes of the general formula (I) are Si2Me2CI4, Si2Me3CI3, Si2Me4CI2 and Si2Me2H4, Si2Me3H3, Si2Me4H2.
Preferred carbodisilanes of the general formula (IV) for the reaction leading to silanes of the general formula (I) are RCI2Si-CH2-SiCI2R, R2CISi-CH2-SiCI2R, R2CISi-CH2-SiCIR2, R3Si-CH2- SiCI2R and R3Si-CH2-SiCIR2, wherein R is as defined above. More preferably, R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, even more preferably from phenyl, vinyl and methyl groups.
Also preferred carbodisilanes of the general formula (IV) for the reaction leading to silanes of the general formula (I) are RH2Si-CH2-SiH2R, R2HSi-CH2-SiH2R, R2HSi-CH2-SiHR2, R3Si- CH2-SiH2R and R3Si-CH2-SiHR2, wherein R is as defined above. More preferably, R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, even more preferably from phenyl, vinyl and methyl groups.
Herein, depending on the degree of methylation and the reaction conditions, the carbodisilanes of the general formula (IV) are either cleaved in the reactions leading to monosilanes of the general formula (I), or they act as hydrogen or chloride donors in redistribution reactions without being cleaved.
In an embodiment according to the invention, due to their generally higher stability towards cleavage in comparison to disilanes with comparable substitution patterns at the silicon atoms, carbodisilanes can at least partially be reused after reacting in redistribution reactions according to the invention.
Preferably, carbodisilanes of the general formula (IV) with o = 0 are submitted to reactions with silane substrates of the general formulae (I I) and optionally (I I I) having no hydrogen substituents as hydrogen donors in the redistribution reactions leading to products of the formula (I) .
More preferably, after such reaction the partially or fully chlorinated carbodisilanes of the general formula (IV) and the partially hydrogenated monosilanes of the general formula (I) are separated by means of distillation, evaporation and/or condensation, and even more preferably thus obtained partially or fully chlorinated carbodisilanes of the general formula (IV) are hydrogenated to carbodisilanes of the general formula (IV) with o = 0 by means of a hydride donor, selected from the group of metal hydrides.
Likewise, in an embodiment according to the invention carbodisilanes of the general formula (IV) partially or fully chlorinated obtained by the redistribution with chlorinated mono- or disilanes of the general formulae (I I) and optionally (I I I) can be regenerated to carbodisilanes of the general formula (IV) with a higher hydrogen content than before by redistribution with fully or mostly hydrogen-substituted organomonosilanes and organodisilanes of the general formulae (I I) and/or (I I I).
Preferably, carbodisilanes of the general formula (IV) with n = 0 are submitted to reactions with silane substrates of the general formulae (I I) and optionally (I I I) having no chlorine substituents as chlorine donors in the redistribution reactions leading to products of the formula (I) .
More preferably, after such reaction the partially or fully hydrogenated carbodisilanes of the general formula (IV) and the partially chlorinated monosilanes of the general formula (I) are separated by means of distillation, evaporation and/or condensation, and even more preferably thus obtained partially or fully hydrogenated carbodisilanes of the general formula (IV) are chlorinated to carbodisilanes of the general formula (IV) with n = 0 by means of a suitable chlorination agent known to the person skilled in the art after isolation from the product mixture.
Likewise, according to the invention carbodisilanes of the general formula (IV) partially or fully hydrogenated obtained by the redistribution with hydrogenated mono- or disilanes of the general formulae (II) and optionally (III) can be regenerated to carbodisilanes of the general formula (IV) with a higher chlorine content than before by redistribution with fully or mostly chlorine-substituted organomonosilanes and organodisilanes of the general formulae (II) and/or (III).
Particularly preferred carbodisilanes of the general formula (IV) for the reactions leading to compounds of the general formula (I) are MeCI2Si-CH2-SiCI2Me, Me2CISi-CH2-SiCI2Me, Me2CISi-CH2-SiCIMe2 and MeH2Si-CH2-SiH2Me, Me2HSi-CH2-SiH2Me, Me2HSi-CH2-SiHMe2.
Preferably, the disilanes and carbodisilanes of the general formulae (III) and (IV) are contained in the Direct Process Residue (DPR), or can be derived from precursors present in the Direct Process Residue by partial or full hydrogenation.
Also preferably, the Direct Process Residue (as received as a side-product of the Direct Process) comprising disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) is submitted to step A).
According to the invention, the term "Direct Process Residue (DPR)" refers to the residues of the Rochow-Muller Direct Process.
The primary current commercial method to prepare alkylhalosilanes and arylhalosilanes is through the Rochow-Muller Direct Process (also called Direct Synthesis or Direct Reaction), in which copper-activated silicon is reacted with the corresponding organohalide, in particular methyl chloride, in a gas-solid or slurry-phase reactor. Gaseous products and unreacted organohalide, along with fine particulates, are continuously removed from the reactor. Hot effluent exiting from the reactor comprises a mixture of copper, metal halides, silicon, silicides, carbon, gaseous organohalide, organohalosilanes, organohalodisilanes, carbosilanes and hydrocarbons. Typically, this mixture is first subjected to gas-solid separation in cyclones and filters. Then the gaseous mixture and ultrafine solids are condensed in a settler or slurry tank from which the organohalide, organohalosilanes, hydrocarbons and a portion of organohalodisilanes and carbosilanes are evaporated and sent to fractional distillation to recover the organohalosilane monomers. The solids accumulated in the settler along with the less volatile silicon-containing compounds are purged periodically and sent to waste disposal or to secondary treatment. Organohalodisilanes and carbosilanes left in the post-distillation residues are also fed to hydrochlorination. Organohalodisilanes, organohalopolysilanes and carbosilanes, related siloxanes and hydrocarbons, either in the post-distillation residues or in the slurry purged from the reactor, boil above orgaohalosilane monomers. Collectively they are referred to as Direct Process Residue (DPR). The terms higher boilers, high-boiling residue and disilane fraction are also used interchangeably with DPR.
Further preferably, silanes of the general formula (III) and (IV), as received from hydrogenation of the DPR, are submitted to step A).
According to the present invention, hydrogenation of the DPR refers to any reaction in which chlorine substituents of silanes of the DPR are exchanged by hydrogen substituents. The resulting product is referred to as "hydrogenated DPR".
According to the present invention, the DPR may be partially or fully hydrogenated, wherein the term fully hydrogenated means that all chlorine substituents at the silicon atoms are exchanged for hydrogen substituents.
Hydrogenation is carried out with a hydride donor, selected from the group of metal hydrides, preferably complex metal hydrides such as LiAIH4, n-Bu3SnH, NaBH4, ( -Bu2AIH)2 or sodium bis(2-methoxyethoxy)aluminumhydride, which is commercially available under the trademarks Vitride® or Red-AI®, for instance, or binary metal hydrides, in particular sodium hydride, lithium hydride or combinations thereof, most preferably lithium hydride.
In accordance with the present invention, a hydride donor is any compound being capable of providing hydride anions for the Si-CI/Si-H exchange in silanes of the formulae (II), (III) and (IV).
In accordance with the present invention, the term metal hydride refers to any hydride donor containing at least one metal atom or metal ion, and preferably includes complex metal hydrides, organometallic reagents and binary metal hydrides.
The term "complex metal hydrides" according to the invention refers to metal salts wherein the anions contain hydrides. Typically, complex metal hydrides contain more than one type of metal or metalloid. In accordance with the present invention the term "metalloid" comprises the elements boron, silicon, germanium, arsenic, antimony, tellurium, carbon, aluminum, selenium, polonium, and astatine.
In an embodiment, preferably, the silanes of the general formula (II) are submitted to the reaction conditions in step A) as single or specific compounds represented by general formula (II), or as a mixture of single or specific compounds represented by general formula (II), or as one or more mixtures comprising one or more single or specific compounds represented by general formula (II). More preferably, single compounds represented by the general formula (II) are submitted to the reaction conditions in step A).
The term "single compound" or "specific compound" in the sense of the present invention means that an isolated compound of at least 90 % purity (purity by weight) is submitted to the reaction of step A).
In preferred compounds (C) selected from the compounds of the general formula R1 4PCI, wherein R1 is hydrogen or an organyl group and can be the same or different. R1 is preferably an aromatic or aliphatic hydrocarbon group, more preferably R1 is an alkyl group, even more preferably R1 is a n-alkyl group, and most preferably the compound of the general formula R1 4PCI is n-Bu4PCI.
In preferred compounds (C) selected from triorganophosphines PR13, wherein R1 is selected from hydrogen and an organyl group and can be the same or different, more preferably R1 is an alkyl, cycloalkyl or aryl group, most preferably the organophosphine is PPh3 or n-Bu3P. R1 in PR13, preferably comprises at least one organyl group.
In preferred compounds (C) selected from triorganoamines N1R3, wherein R1 is selected from hydrogen and an organyl group, preferably an organyl group, more preferably R1 is an alkyl group, and most preferably the triorganoamine is n-Bu3N or NPh3.
Preferred compounds (C) selected from N-heterocyclic amines are methylimidazoles such as 2-methylimidazole, 4-methylimidazole and 1-methylimidazole, most preferably 2- methylimidazole.
In preferred compounds (C) selected from quaternary ammonium compounds N1R4CI, wherein R1 is an organyl group and can be the same or different, more preferably R1 is an alkyl group, and most preferably the quaternary ammonium compound is n-Bu4NCI.
The optional step of separating the resulting chlorohydridomonosilanes of the general formula (I) refers to any technical means applied to raise the content of one or more methylmonosilanes according to the general formula (I) in a product or reaction mixture, or which results in the separation of one or more single compounds of the formula (I) from a product or reaction mixture obtained in step A) of the process according to the invention.
Further preferably, the reaction step A) is carried out in a suitably sized reactor made of materials that are resistant to corrosion by chlorides, such as glass or Hastelloy C. Vigorous agitation may be used to disperse or dissolve the compound (C) and the metal hydride in the reaction mixture.
In a preferred embodiment of the process according to the invention, step A) is carried out in an organic solvent or mixtures thereof, preferably a high-boiling ether compound, more preferably 1 ,4-dioxane, diglyme or tetraglyme, most preferably diglyme. According to the present invention, the term "organic solvent" refers to any organic compound or mixtures thereof which is in liquid state at room temperature, and which is suitable as a medium for conducting the redistribution reactions of step A) therein. Accordingly, the organic solvent is preferably inert to the compounds (C) according to present invention under reaction conditions. Furthermore, the starting materials of the general formulae (II), (III) and (IV) and the products of the general formula (I) are preferably soluble in the organic solvent or fully miscible with the organic solvent, respectively.
Preferably, the organic solvent is selected from optionally substituted, preferably unsubstituted linear or cyclic aliphatic hydrocarbons, aromatic hydrocarbons or ether compounds, without being limited thereto.
Herein, the term "ether compound" shall mean any organic compound containing an ether group -O- (one or more ether groups are possible), in particular of the formula R2-0-R3, wherein R2 and R3 are independently selected from an organyl group R as defined above. In general, the organyl group R can be selected for example from optionally substituted, preferably unsubstituted, alkyl, aryl, alkenyl, alkynyl, alkaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, cycloaralkyl, cycloaralkenyl, and cycloaralkynyl groups, preferably from alkyl, alkenyl and aryl groups.
Preferably, R3 and R2 are substituted or unsubstituted linear or branched alkyl groups or aryl groups, which may have further heteroatoms such as oxygen, nitrogen, or sulfur. In the case of cyclic ether compounds, R3 and R2 can constitute together an optionally substituted alkylene or arylene group, which may have further heteroatoms such as oxygen, nitrogen, or sulfur, as for instance in dioxanes, in particular 1 ,4-dioxane.
The ether compounds can be symmetrical or asymmetrical with respect to the substituents at the ether group(s) -0-.
The term "ether compound" according to the invention also comprises linear ether compounds in which more than one ether group may be included, forming a di-, tri-, oligo- or polyether compound, wherein R3 and R2 constitute organyl groups when they are terminal groups of the compounds, and alkylene or arylene groups when they are internal groups. Herein, a terminal group is defined as any group being linked to one oxygen atom which is part of an ether group, while an internal group is defined as any group linked to two oxygen atoms being a constituent of ether groups.
Preferred examples of such compounds are dimethoxy ethane, glycol diethers (glymes), in particular diglyme or tetraglyme, without being limited thereto.
According to the present invention, the term "high-boiling ether compound" is defined as an ether compound according to the above definition with a boiling point at about 1 .01325 bar (standard atmosphere pressure) of preferably at least about 70 °C, more preferably at least about 85 °C, even more preferably at least about 100 °C, and most preferably at least about 120 °C.
The application of high-boiling ethers in the present invention is favourable as it facilitates separation of the desired products of the general formula (I) from the reaction mixture containing the solvent and residual starting materials. The products of the general formula (I) in general have lower boiling points than the high-boiling ethers as defined herein.
For example, the boiling points of selected representative products of the general formula (I) are 35 °C (Me2SiHCI) and 41 °C (MeSiHC ) at atmospheric pressure, while the representative higher-boiling ether compound diglyme has a boiling point of 162 °C at standard atmosphere pressure. Application of higher-boiling ether compounds as solvents allows higher reaction temperatures and allows a more efficient separation of the desired products from the reaction mixture by distillation.
In another preferred embodiment of the process according to the invention, step A) is carried out in the presence of one or more hydride donors, preferably one or more metal hydrides, more preferably one or more metal hydrides selected from the group of alkali metal hydrides and alkaline earth metal hydrides, and most preferably lithium hydride.
According to the present invention, the term "hydride donor" refers to any compound which is capable of donating at least one hydride anion in a reaction of any of the silane substrates of the general formulae (I I), (I II) and (IV) leading to a product of the general formula (I).
The term "organometallic hydride reagent" refers to compounds that contain bonds between carbon and metal atoms, and which are capable of donating at least one hydride anion used in a reaction of substrates of the general formulae (I I), (I II) or (IV) leading to the products of the general formula (I).
Binary metal hydrides in accordance with the present invention are metal hydrides consisting of ions of one specific metal and hydride ions exclusively.
Preferably, the metal hydrides according to the invention are selected from binary metal hydrides, more preferably selected from alkali metal hydrides and earth alkaline metal hydrides, even more preferably selected from the group of lithium hydride, sodium hydride, potassium hydride, magnesium hydride, calcium hydride, even more preferably from lithium hydride and sodium hydride, most preferably the metal hydride is lithium hydride.
In another preferred embodiment of the process according to the invention, in general formula (I) and one or more of the silanes of the general formulae (I I) R is an alkyl or cycloalkyl group, preferably a methyl group.
Preferably, in general formula (I) and one or more of the silanes of the general formulae (I I) R is an alkyl or cycloalkyl group, more preferably an alkyl or cycloalkyl group having about 1 to about 20 carbon atoms, even more preferably an alkyl or cycloalkyl group having about 1 to about 10 carbon atoms, even further preferably about 1 to about 6 carbon atoms, and most preferably R is a methyl group.
In a preferred embodiment of the process according to the invention, the silanes submitted to the reaction comprise one or more silanes selected from the group of
monosilanes of the general formula (I I) with b = 0,
disilanes of the general formula (I I I) with f = 0, and
carbodisilanes of the general formula (IV) with n = 0,
that is, the silanes do not have hydrogen substituents.
Preferably, the monosilanes of the general formula (I I) submitted to the reaction with b = 0 having no hydrogen substituents are reacted with silanes of the general formulae (I I I) and (IV) having no chlorine substituents but having hydrogen substituents at the silicon atoms, more preferably monosilanes of the general formula (I I) submitted to the reaction with b = 0 having no hydrogen substituents are selected from R2SiCI2 and RSiCI3 and reacted with disilanes of the general formula (I I I) selected from S12R2H4, S12R3H3 and S12R4H2 or carbodisilanes of the general formula (IV) with o = 0, wherein R is selected from cycloalkyl, alkyl, aryl and alkenyl groups and can be the same or different, even more preferably the monosilanes of the general formula (I I) submitted to the reaction with b = 0 are selected from R2S1CI2 and RSiC and reacted with disilanes of the general formula (I I I) selected from S12R2H4, S12R3H3 and S12R4H2 or carbodisilanes of the general formula (IV) with o = 0, wherein R is selected from methyl, vinyl and phenyl and can be the same or different, and most preferably Me2SiCI2 or MeSiC is reacted with disilanes selected from Si2Me2H4,
Figure imgf000017_0001
Also preferably, the monosilanes of the general formula (I I) submitted to the reaction with b = 0 having no hydrogen substituents are reacted with silanes of the general formulae (I II) and (IV) having also no hydrogen substituents at the silicon atoms in the presence of lithium hydride, more preferably monosilanes of the general formula (I I) submitted to the reaction with b = 0 are selected from R2SiCI2 and RSiCI3 and reacted with disilanes of the general formula (I II) selected from S12R2CI4, S12R3CI3 and S12R4CI2 or carbodisilanes of the general formula (IV) with n = 0, wherein R is selected from cycloalkyl, alkyl, aryl and alkenyl groups and can be the same or different, in the presence of lithium hydride, even more preferably the monosilanes of the general formula (I I) submitted to the reaction with b = 0 are selected from R2S1CI2 and RSiCI3 and reacted with disilanes selected from S12R2CI4, S12R3CI3 and S12R4CI2 or carbodisilanes of the general formula (IV) with n = 0, wherein R is selected from methyl, vinyl and phenyl and can be the same or different, in the presence of lithium hydride, and most preferably Me2SiCI2 or MeSiCI3 is reacted with disilanes selected from Si2Me2CI4, Si2Me3CI3 and Si2 Me4CI2 in the presence of lithium hydride.
Preferably, the disilanes of the general formula (III) submitted to the reaction with f = 0 having no hydrogen substituents are reacted with silanes of the general formulae (II) and (IV) having no chlorine substituents at the silicon atoms, more preferably disilanes of the general formula (III) submitted to the reaction with f = 0 are selected from CI2RSi-SiRCI2, CI2RSi-SiR2CI and CIR2Si-SiR2CI and reacted with monosilanes selected from R2SiH2 and RSiH3 or carbodisilanes of the general formula (IV) with o = 0, wherein R is selected from cycloalkyl, alkyl, aryl and alkenyl groups and can be the same or different, even more preferably the disilanes of the general formula (III) submitted to the reaction with f = 0 are selected from CI2RSi-SiRCI2, CI2RSi-SiR2CI and CIR2Si-SiR2CI and reacted with monosilanes selected from R2SiH2 and RSiH3 or carbodisilanes of the general formula (IV) with o = 0, wherein R is selected from methyl, vinyl and phenyl and can be the same or different, and most preferably CI2MeSi-SiMeCI2, CI2MeSi-SiMe2CI and CIMe2Si-SiMe2CI is reacted with monosilanes selected from Me2SiH2 and MeSiH3 and Si2Me4H2 or methylcarbodisilanes with o = 0.
Also preferably, the disilanes of the general formula (III) submitted to the reaction with f = 0 having no hydrogen substituents are reacted with silanes of the general formulae (II) and (IV) having also no hydrogen substituents at the silicon atoms in the presence of lithium hydride, more preferably the disilanes of the general formula (III) submitted to the reaction with f = 0 are selected from CI2RSi-SiRCI2, CI2RSi-SiR2CI and CIR2Si-SiR2CI and reacted with monosilanes selected from R2SiCI2 and RSiCI3 or carbodisilanes of the general formula (IV) with n = 0, wherein R is selected from cycloalkyl, alkyl, aryl and alkenyl groups and can be the same or different in the presence of lithium hydride, even more preferably the disilanes of the general formula (III) submitted to the reaction with f = 0 are selected from CI2RSi-SiRCI2, CI2RSi-SiR2CI and CIR2Si-SiR2CI and reacted with monosilanes selected from R2SiCI2 and RSiCI3 or carbodisilanes of the general formula (IV) with n = 0, wherein R is selected from methyl, vinyl and phenyl and can be the same or different, in the presence of lithium hydride, and most preferably CI2MeSi-SiMeCI2, CI2MeSi-SiMe2CI or CIMe2Si-SiMe2CI is reacted with monosilanes selected from MeSiCI3 and Me2SiCI2.
Preferably, the carbodisilanes of the general formula (IV) with n = 0 having no hydrogen substituents are submitted to the reaction with one or more silanes selected from the monosilanes of the general formula (II) selected from R2SiH2 and RSiH3 and from the disilanes of the general formula (III) selected from Si2R2H4, Si2R3H3 and Si2R H2 wherein R is selected from cycloalkyl, alkyl, aryl and alkenyl groups and can be the same or different, more preferably the carbodisilanes of the general formula (IV) with n = 0 are submitted to the reaction with one or more silanes selected from the monosilanes of the general formula (II) selected from R2SiH2 and RSiH3 and from the disilanes of the general formula (III) selected from S12R2H4, S12R3H3 and S12R4H2, wherein R is selected from methyl, vinyl and phenyl and can be the same or different.
Even more preferably the carbodisilanes of the general formula (IV) with n = 0 and having more than three chlorine substituents, most preferably the carbodisilanes of the general formula (IV) with n = 0 and o = 4 or 5 are submitted to the reaction with one or more silanes selected from the monosilanes of the general formula (I I) selected from R2SiH2 and RS1H3 and from the disilanes of the general formula (III) selected from S12R2H4, S12R3H3 and S12R4H2, wherein R in the silanes of the general formulae (II) and (III) is selected from methyl, vinyl and phenyl and can be the same or different, and wherein R in the carbodisilanes of the general formula (IV) is methyl.
In a further preferred embodiment of the process according to the invention, for all monosilanes of the general formula (II) subjected to the reaction in step A), c = 0.
Preferably, when for all monosilanes of the general formula (II) subjected to the reaction in step A), c = 0, greater than about 50% of the number of substituents at the silicon atoms of the silanes of the general formulae (II I) and/or (IV) submitted to step A) other than R are chlorine substituents, more preferably greater than about 75% of the number of substituents are chlorine substituents, and most preferably greater than about 90% of the number of substituents other than R at the silicon atoms of the silanes of the general formulae (I II) and (V) submitted to step A) are chlorine substituents.
In the determination of the percentage of chlorine substituents at the silicon atoms in the molecules of the silane substrate, only hydrogen and chlorine substituents are taken into consideration.
Also preferably, when for all monosilanes of the general formula (II) subjected to the reaction in step A), c = 0, greater than about 50 mol-% of the silanes of the general formulae (III) and (IV) submitted to step A) do not have hydrogen substituents at the silicon atoms, more preferably greater than about 70 mol-% do not have hydrogen substituents at the silicon atoms, even further preferably, greater than about 90 mol-% do not have hydrogen substituents at the silicon atoms, and most preferably greater than about 95 mol-% of the silanes of the general formulae (II I) and (IV) submitted to step A) do not have hydrogen substituents at the silicon atoms.
The molar ratio of silanes of the general formulae (III) and (IV) not having hydrogen substituents at the silicon atoms to silanes of the general formulae (III) and (IV) is defined as n (silanes of the general formulae (III) and (IV) not having hydrogen substituents at the silicon atoms)/ n (silanes of the general formulae (III) and (IV)).
Preferably, when for all monosilanes of the general formula (II) subjected to the reaction in step A), c = 0, the silanes of the general formulae (III) and (IV) are obtained from the Direct Process Residue and greater than about 80% of the number of substituents of the silanes of the general formulae (III) and (IV) at the silicon atoms are chlorine substituents, or the monosilanes of the general formula (I I) are submitted to step A) with Direct Process Residue comprising silanes of the general formulae (I II) or (IV) as obtained as side-product from the Direct Process.
Again, in the determination of the percentage of chlorine substituents at the silicon atoms in the molecules of the silane substrate, only hydrogen and chlorine substituents are taken into consideration.
In another preferred embodiment of the process according to the invention, for all monosilanes of the general formula (II) subjected to the reaction in step A), b = 0.
Preferably, when for all monosilanes of the general formula (II) subjected to the reaction in step A), b = 0, greater than about 50% of the number of substituents at the silicon atoms of the silanes of the general formulae (III) and (IV) submitted to step A) other than R are hydrogen substituents, more preferably greater than about 75% of the number of substituents are hydrogen substituents, and most preferably greater than about 90% of the number of substituents other than R at the silicon atoms of the silanes of the general formulae (III) and (V) submitted to step A) are hydrogen substituents.
In the determination of the percentage of hydrogen substituents at the silicon atoms in the molecules of the silane substrate, only hydrogen and chlorine substituents are taken into consideration.
Also preferably, when for all monosilanes of the general formula (II) subjected to the reaction in step A), b = 0, greater than about 50 mol-% of the silanes of the general formulae (III) and (IV) submitted to step A) do not have chlorine substituents at the silicon atoms, more preferably greater than about 70 mol-% do not have chlorine substituents at the silicon atoms, even further preferably, greater than about 90 mol-% do not have chlorine substituents at the silicon atoms, and most preferably more than about 95 mol-% of the silanes of the general formulae (III) and (IV) submitted to step A) do not have chlorine substituents at the silicon atoms.
The molar ratio of silanes of the general formulae (III) and (IV) not having chlorine substituents at the silicon atoms to silanes of the general formulae (III) and (IV) is defined as n (silanes of the general formulae (III) and (IV) not having chlorine substituents at the silicon atoms)/ n (silanes of the general formulae (III) and (IV)). Preferably, when for all monosilanes of the general formula (I I) subjected to the reaction in step A) b = 0, the silanes of the general formulae (I I I) and (IV) are derived from the Direct Process Residue by hydrogenation and greater than about 80% of the number of substituents of the silanes of the general formulae (I I I) and (IV) at the silicon atoms are hydrogen substituents, or the monosilanes of the general formula (I I) are submitted to step A) with hydrogenated Direct Process Residue comprising silanes of the general formulae (I I I) or (IV) as obtained by hydrogenation reaction of the side-product from the Direct Process.
Again, in the determination of the percentage of hydrogen substituents at the silicon atoms in the molecules of the silane substrate, only hydrogen and chlorine substituents are taken into consideration.
In another further preferred embodiment of the process according to the invention, for all monosilanes of the general formula (I I) subjected to the reaction in step A) c = 0, and for all disilanes of the general formula (I II) f = 0 and for all carbodisilanes of the general formula (IV) n = 0.
Preferably the monosilanes of the general formula (I I) are R2SiH2 and RSiH3, more preferably the monosilanes of the general formula (I I) are R2SiH2 and RSihh, wherein R is selected from vinyl, phenyl and methyl, even more preferably the monosilanes of the general formula (I I) are selected from Me2SiH2 and MeSiH3, and most preferably the monosilanes of the general formula (II) are selected from Me2SiH2 and MeSiH3, and the silanes of the general formulae (II I) and (IV) are selected from the group of Si2Me2Cl4, Si2Me3CI3, Si2Me4CI2, (SiCH2Si)Me2CI4, (SiCH2Si)Me3CI3 and (SiCH2Si)Me2CI4, and optionally are part of a Direct Process Residue (DPR) .
In a preferred embodiment of the process according to the invention, for all monosilanes of the general formula (I I) subjected to the reaction in step A) b = 0, and for all disilanes of the general formula (I I I) g = 0 and for all carbodisilanes of the general formula (IV) o = 0.
Preferably the monosilanes of the general formula (I I) are R2SiCI2 and RSiCI3, more preferably the monosilanes of the general formula (II) are R2SiCI2 and RSiCI3, wherein R is selected from vinyl, phenyl and methyl, even more preferably the monosilanes of the general formula (I I) are selected from Me2SiCI2 and MeSiCI3, and most preferably the monosilanes of the general formula (I I) are selected from Me2SiCI2 and MeSiCI3, and the silanes of the general formulae (I I I) and (IV) are selected from the group of Si2Me2H4, Si2Me3H3, Si2Me H2, (SiCH2Si)Me2H4, (SiCH2Si)Me3H3 and (SiCH2Si)Me2H4, and optionally are part of a hydrogenation product of the Direct Process Residue (DPR).
In a likewise preferred embodiment of the process according to the invention, silane substrates of the general formulae (II) , (I I I) or (IV) having one or more hydrogen substituents at the silicon atom(s) in step A) are prepared by a hydrogenation reaction prior to step A).
Herein, all silane substrates of the general formulae (II), (III) or (IV) having one or more hydrogen substituents at the silicon atom(s) in step A) may be prepared by a hydrogenation step prior to step A), or only a part of the silane substrates of the general formulae (II), (III) or (IV) having one or more hydrogen substituents at the silicon atom(s) in step A) may be prepared by a hydrogenation reaction prior to step A).
According to this embodiment, the term "atom(s)" shall be understood in the way that above- given description of the preferred embodiment applies to the sole silicon atom in monosilanes of the general formula (II), and to at least one of the silicon atoms in silanes of the general formulae (III) and (IV).
According to the invention, the term "hydrogenation" refers to the exchange of one or more chlorine substituents at silicon atoms by the same number of hydrogen substituents.
Preferably, the hydrogenation reactions prior to step A) leading to hydrogenated silane substrates of the general formulae (II), (I II) and (IV) are performed with a hydride donor selected from the group of metal hydrides, preferably complex metal hydrides and organometallic hydride reagents such as LiAIH4, n-Bu3SnH, NaBH4, /-Bu2AIH or sodium bis(2-methoxyethoxy) aluminum hydride.
In a further preferred embodiment of the process according to the invention, the amount of the metal hydride in step A) in relation to the silane substrate compounds to be hydrogenated is in the range of about 0.05 mol-% to about 395.95 mol-%, preferably about 20 mol-% to about 200 mol-%, more preferably about 50 mol-% to about 150 mol-%, and most preferably about 80 mol-% to about 100 mol-%. Herein, the molar ratio in % is defined as
[n (metal hydride added to the reaction mixture in step A)) / n (silane substrate compounds of the general formulae (II), (III) and/or (IV) )] x 100.
For the determination of this molar ratio, the compounds selected from monosilanes of the general formula (II), disilanes of the general formula (III) and carbodisilanes of the general formula (IV) are considered, regardless if they are submitted as a part of a mixture comprising other compounds, in particular monosilanes, disilanes and carbodisilanes, which do not fall under the general formulae (II), (III) or (IV), respectively.
In a further preferred embodiment of the process according to the invention, the amount of the one or more compounds (C) in step A) in relation to the silane substrate compounds is in the range of about 0.0001 mol-% to about 600 mol-%, more preferably about 0.01 mol-% to about 20 mol-%, even more preferably about 0.05 mol-% to about 2 mol-%, and most preferably about 0.05 mol-% to about 1 mol-%. Herein, the molar ratio in % is defined as [n (compound or compounds (C) in step A)) / n (silane substrate compounds of the general formulae (II), (III) and (IV) in step A))] x 100.
For the determination of this molar ratio, all compounds falling under the definition of the compound (C), are considered, and all compounds being monosilanes of the general formula (II), disilanes of the general formula (III) and carbodisilanes of the general formula (IV) submitted to the reaction step A) are considered, regardless if they are submitted as a part of a mixture comprising other compounds, in particular disilanes and carbodisilanes which do not fall under the general formulae (II), (III) or (IV).
In a preferred embodiment of the process according to the invention, in the step A) the weight ratio of the silane substrates to the organic solvent(s) is in the range of about 0.01 to about 100, preferably in the range of about 0.1 to about 10, more preferably about 0.5 to about 4, most preferably about 0.5 to about 1. Herein, the weight ratio is defined as m (silane substrate compounds of the general formulae (II), (III) and (IV) in step A)) / m (organic solvents in step A)).
For the determination of this ratio, all compounds being monosilanes of the general formula (II), disilanes of the general formula (III) and carbodisilanes of the general formula (IV) submitted to the reaction step A) are considered, regardless if they are submitted as a part of a mixture comprising other compounds, in particular disilanes and carbodisilanes which do not fall under the general formulae (II), (III) or (IV).
In a preferred embodiment of the process according to the invention, the step A) is conducted at a temperature of about 0 °C to about 300 °C, preferably about 20 °C to about 200 °C, more preferably about 80 °C to about 200 °C. According to the invention, the reaction temperature in step A) is the temperature of the reaction mixture, i.e. the temperature measured inside the reaction vessel in which the reaction is conducted.
In another preferred embodiment of the process according to the invention, the step A) is conducted at a pressure of about 0.1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
The indicated pressure ranges refer to the pressure measured inside the reaction vessel used when conducting reaction step A).
In a further preferred embodiment of the process according to the invention, the monosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSiHC and MeSihbCI.
Preferably, the monosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me2SiCl2 to the reaction step A), more preferably the monosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me2SiCI2 and one or more silanes of the general formulae (III) or (IV) having no chlorine substituents to the reaction step A), even more preferably the monosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me2SiCI2 and one or more silanes selected from the group of the silanes of empirical formulae Si2Me2H4, Si2Me3H3, Si2Me4H2, (SiCH2Si)Me2H4, (SiCH2Si)Me3H3 and (SiCH2Si)Me4H2 to the reaction step A), most preferably the monosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me2SiCI2 and Si2H2Me to the reaction step A).
Further preferably, the monosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me2SiH2 to the reaction step A), more preferably the monosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me2SiH2 and one or more silanes of the general formulae (III) or (IV) having no hydrogen substituents to the reaction step A), even more preferably the monosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me2SiH2 and one or more silanes selected from the group of the silanes of empirical formulae Si2Me2CI4, Si2Me3CI3, Si2Me4CI2, (SiCH2Si)Me2CI4, (SiCH2Si)Me3CI3 and (SiCH2Si)Me CI2 to the reaction step A), most preferably the methylmonosilane of the formula (I) is Me2SiHCI and it is produced by submitting Me2SiH2 and Si2Me4CI2 to the reaction step A).
Also preferably, the monosilane of the formula (I) is MeSiHCb, and it is produced by submitting MeSiCI3 to the reaction step A), more preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiCI3 and one or more silanes of the general formulae (III) or (IV) having no chlorine substituents to the reaction step A), even more preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiC and one or more silanes selected from the group of the silanes of empirical formulae Si2Me2H4, Si2Me3H3, Si2Me4H2, (SiCH2Si) Me2H4, (SiCH2Si)Me3H3 and (SiCH2Si)Me4H2 to the reaction step A), most preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiCb and Si2Me2H4 to the reaction step A).
Further preferably, the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiH3 to the reaction step A), more preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiH3 and one or more silanes of the general formulae (III) or (IV) having no hydrogen substituents to the reaction step A), even more preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiH3 and one or more silanes selected from the group of the silanes of empirical formulae Si2Me2CI4, Si2Me3CI3, Si2Me4CI2, (SiCH2Si)Me2CI4, (SiCH2Si)Me3CI3 and (SiCH2Si)Me4CI2 to the reaction step A), most preferably the monosilane of the formula (I) is MeSiHCb and it is produced by submitting MeSiH3 and Si2Me2CI to the reaction step A). In a further preferred embodiment of the process according to the invention, the silanes of the general formula (II) are selected from the group consisting of Me2SiCI2, MeSiCb, Me2SiH2 and MeSihh.
Preferably, Me2SiCI2 is selected as a starting material for the production of Me2SiHCI in step A), more preferably Me2SiCI2 is selected as a starting material for the production of Me2SiHCI in step A) by the reaction with one or more silanes selected from the silanes of empirical formulae Si2Me4H2 and (SiCH2Si)Me4H2, most preferably Me2SiCI2 is selected as a starting material for the production of Me2SiHCI in step A) by the reaction with Si2Me4H2.
Also preferably, MeSiCb is selected as a starting material for the production of MeSiHCI2 in step A), more preferably MeSiCb is selected as a starting material for the production of MeSiHCb in step A) by the reaction with one or more silanes selected from the group of the silanes of empirical formulae consisting of Si2Me2H4 and (SiCH2Si) Me2H , most preferably MeSiCb is selected as a starting material for the production of MeSiHCb in step A) by the reaction with Si2 Me2H .
Further preferably, Me2SiH2 is selected as a starting material for the production of Me2SiHCI in step A), more preferably Me2SiH2 is selected as a starting material for the production of Me2SiHCI in step A) by the reaction with one or more silanes selected from the silanes of empirical formulae Si2Me4CI2 or (SiCH2Si)Me4CI2, most preferably Me2SiH2 is selected as a starting material for the production of Me2SiHCI in step A) by reaction with Si2Me CI2.
Also preferably, MeSiH3 is selected as a starting material for the production of MeSiHCb in step A), more preferably MeSihb is selected as a starting material for the production of MeSiHCb in step A) in the presence of one or more silanes selected from the group of the silanes of empirical formulae Si2Me2CI and/or (SiCH2Si)Me2CI , most preferably MeSiH3 is selected as a starting material for the production of MeSiHCb in step A) by reaction with Si2Me2CI4
In the reactions of disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) according to the invention, the disilanes and carbodisilanes can act as hydride donors or hydride acceptors in redistribution reactions with monosilanes of the general formula (II), and they can be cleaved to monosilanes of the general formulae (II) and (I) under the reaction conditions of step A) in the presence of the compounds (C).
In a preferred embodiment of the process according to the invention, the silanes of the general formulae (III) are selected from the group of MeH2Si-SiH2Me, MeH2Si-SiHMe2, Me2HSi-SiHMe2, MeCI2Si-SiCI2Me, MeCI2Si-SiCIMe2 and Me2CISi-SiCIMe2.
Preferably, MeH2Si-SiH2Me and/or MeH2Si-SiHMe2 is/are selected as a starting material for the production of MeSiHCb in step A), more preferably MeH2Si-SiH2Me is selected as a starting material for the production of MeSiHCb in step A), even more preferably MeH2Si- SiH2Me is selected as a starting material for the production of MeSiHCb by the reaction with one or more silanes selected from MeSiCb or (SiCH2Si)Me2Cl4, most preferably MeH2Si- SiH2Me is selected as a starting material for the production of MeSiHCb in step A) by the reaction with MeSiCI3.
Also preferably, Me2HSi-Sil-IMe2 and/or MeH2Si-SiHMe2 is/are selected as a starting material for the production of Me2SiHCI in step A), more preferably Me2HSi-SiHMe2 is selected as a starting material for the production of Me2SiHCI in step A), even more preferably Me2HSi- SiHMe2 is selected as a starting material for the production of Me2SiHCI by the reaction with one or more silanes selected from Me2SiCI2 and (SiCH2Si)Me4CI2, most preferably Me2HSi- SiHMe2 is selected as a starting material for the production of Me2SiHCI in step A) by the reaction with Me2SiCI2.
Preferably, MeCI2Si-SiCI2Me and/or MeCI2Si-SiCIMe2 is/are selected as a starting material for the production of MeSiHCI2 in step A), more preferably MeCI2Si-SiCI2Me is selected as a starting material for the production of MeSiHCI2 in step A), even more preferably MeCbSi- SiCI2Me is selected as a starting material for the production of MeSiHCb by the reaction with one or more silanes selected from MeSiH3 and (SiCH2Si)Me2H4, most preferably MeCbSi- SiCI2Me is selected as a starting material for the production of MeSiHCb in step A) by the reaction with MeSihb.
Also preferably, Me2CISi-SiCIMe2 and/or MeCI2Si-SiCIMe2 is/are selected as a starting material for the production of Me2SiHCI in step A), more preferably Me2CISi-SiCIMe2 is selected as a starting material for the production of Me2SiHCI in step A), even more preferably Me2CISi-SiCIMe2 is selected as a starting material for the production of Me2SiHCI by the reaction with one or more silanes selected from Me2SiH2 and (SiCH2Si)Me4H2, most preferably Me2CISi-SiCIMe2 is selected as a starting material for the production of Me2SiHCI in step A) by the reaction with Me2SiH2.
In another preferred embodiment of the process according to the invention the carbodisilanes of the general formula (IV) are selected from the group consisting of MeH2(SiCH2Si)H2Me, MeH2(SiCH2Si)HMe2, Me2H(SiCH2Si)HMe2, MeCb(SiCH2Si)CI2Me, MeCb(SiCH2Si)CIMe2 and Me2CI(SiCH2Si)CIMe2.
Preferably, MeH2(SiCH2Si)H2Me and/or MeH2(SiCH2Si)HMe2 is/are selected as a starting material for the production of MeSiHCb in step A), more preferably MeH2(SiCH2Si)H2Me is selected as a starting material for the production of MeSiHCb in step A), even more preferably MeH2(SiCH2Si)H2Me is selected as a starting material for the production of MeSiHCb by the reaction with one or more silanes selected from the silanes of empirical formulae MeSiC and Si2Me2CI4, most preferably MeH2(SiCH2Si)H2Me is selected as a starting material for the production of MeSiHC in step A) by the reaction with MeSiCI3.
Also preferably, Me2H(SiCH2Si)HMe2 and/or MeH2(SiCH2Si)HMe2 is/are selected as a starting material for the production of Me2SiHCI in step A), more preferably Me2H(SiCH2Si)HMe2 is selected as a starting material for the production of Me2SiHCI in step A), even more preferably Me2H(SiCH2Si)HMe2 is selected as a starting material for the production of Me2SiHCI by the reaction with one or more silanes selected from Me2SiCI2 and Si2Me4Cl2, most preferably Me2H(SiCH2Si)HMe2 is selected as a starting material for the production of Me2SiHCI in step A) by the reaction with Me2SiCI2.
Preferably, MeCI2(SiCH2Si)CI2Me and/or MeCI2(SiCH2Si)CIMe2 is/are selected as a starting material for the production of MeSiHC in step A), more preferably MeC CSiChbSrjChMe is selected as a starting material for the production of MeSiHC in step A), even more preferably MeChCSiChbSrjChMe is selected as a starting material for the production of MeSiHC by the reaction with one or more silanes selected from MeSiH3 and Si2Me2H4, most preferably MeChCSiChbSrjChMe is selected as a starting material for the production of MeSiHC in step A) by the reaction with MeSiH3.
Also preferably, Me2CI(SiCH2Si)CIMe2 and/or MeCI2(SiCH2Si)CIMe2 is/are selected as a starting material for the production of Me2SiHCI in step A), more preferably Me2CI(SiCH2Si)CIMe2 is selected as a starting material for the production of Me2SiHCI in step A), even more preferably Me2CI(SiCH2Si)CIMe2 is selected as a starting material for the production of Me2SiHCI by the reaction with one or more silanes selected from Me2SiH2 and Si2Me4H2, most preferably Me2CI(SiCH2Si)CIMe2 is selected as a starting material for the production of Me2SiHCI in step A) by the reaction with Me2SiH2.
In another preferred embodiment of the process according to the invention, step A) is carried out in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above.
Preferably, in the formula R1 4PCI R1 is a hydrogen or an organyl group, as defined above, which can be the same or different, more preferably R1 is an aromatic group or an aliphatic hydrocarbon group, even more preferably R1 is an alkyl or cycloalkyl group, even further preferably R1 is a n-alkyl group, and most preferably the compound of the general formula R1 4PCI is n-Bu PCI.
In the present invention, a compound (C) of the formula R1 4PCI acts as a catalyst for the redistribution reaction in step A), and may also act as a reagent for the cleavage of disilanes and carbodisilanes of the general formulae (III) or (IV). In a further preferred embodiment of the process according to the invention, wherein the compounds of formula R1 4PCI are formed in situ from compounds of the formulae R1 3P and R1CI, wherein R1 is H or an organyl group, preferably R1 is at least one organyl group, preferably all R1 are organyl groups.
According to the invention, R1 in R1 4PCI formed in situ is H or an organyl group and can be the same or different, and preferably R1CI is HCI or a chloroalkane, more preferably the R are the same and R1CI is a 1 -chloroalkane with up to about 20 carbon atoms, even more preferably the R1 are the same and R1CI is a 1 -chloroalkane with up to about 10 carbon atoms, and most preferably the R1 are the same and R1CI is 1 -chlorobutane.
The term "formed in situ" in accordance with the invention means that the compound R1 4PCI is formed from R13P and R1CI by combination of these compounds in the reaction vessel in which reaction step A) is performed, or by combination of these compounds in a separate reaction vessel prior to step A) and addition of this mixture to reaction step A) without further work-up.
In another preferred embodiment of the process according to the invention, step A) is carried out in the presence of at least one compound of the formula (C) , preferably R1 4PCI, and lithium hydride.
Preferably, step A) is carried out in the presence of lithium hydride and at least one compound of the formula R1 4PCI, wherein R1 is an organyl group and can be the same or different. More preferably, step A) is carried out as described above, wherein the silane substrates of the general formulae (II), (II I) or (IV) do not have any hydrogen substituents at the silicon atoms. Even more preferably, step A) is carried out as described before, wherein the monosilane of the general formula (I I) submitted to the reaction is selected from the group of Me2SiC and MeSiC .
In a particular preferred embodiment of the process according to the invention, step A) is carried out in the presence of n-Bu4PCI.
In the experiments according to the invention, n-Bu PCI was found to be a particularly effective redistribution catalyst, and also an effective reagent for the cleavage of disilanes and carbodisilanes. The term cleavage of disilanes refers to the cleavage of the Si-Si bond leading to the formation, while the term cleavage of carbodisilanes refers to the cleavage of the bonds connecting the silicon atoms to the methylene unit linking the two silicon atoms of the carbodisilanes.
Preferably, step A) is carried out in the presence of n-Bu PCI and in the presence of a high- boiling ether compound, more preferably step A) is carried out in the presence of lithium hydride and a high-boiling ether compound selected from the group of diglyme, tetraglyme and 1 ,4-dioxane and mixtures thereof, most preferably in the presence of a high-boiling ether compound selected from the group of diglyme, tetraglyme and 1 ,4-dioxane, and mixtures thereof and lithium hydride.
Also preferably, step A) is carried out in the presence of n-Bu PCI, wherein Me2SiCI2 or MeSiCb is submitted to the reaction step, more preferably step A) is carried out in the presence of n-Bu PCI, wherein Me2SiCI2 or MeSiCb is submitted to the reaction step in the further presence of lithium hydride.
Further preferably, step A) is carried out in the presence of n-Bu PCI, wherein the silane substrate submitted to the reaction comprises disilanes of the general formula (III), more preferably disilanes of the general formula (III) not bearing any hydrogen substituents at the silicon atoms, most preferably the disilanes of the general formula (III) are selected from the group of the empirical formulae Si2Me2CI4, Si2Me3CI3 and Si2Me CI2.
In a further preferred embodiment of the process according to the invention, step A) is carried out in the presence of n-Bu PCI and lithium hydride.
Preferably, the products obtained from step A) carried out in the presence of n-Bu PCI and lithium hydride are selected from the compounds of the general formulae (I) RSiHCb and R2SiHCI, wherein R is selected from cycloalkyl, alkyl, aryl and alkenyl groups, more preferably R in RSiHCb and R2SiHCI obtained from step A) carried out in the presence of n- Bu4PCI and lithium hydride is selected from the group consisting of methyl, vinyl and phenyl groups, and most preferably R is a methyl group.
Also preferably, in step A) Me2SiHCI is produced in the presence of n-Bu PCI and lithium hydride by the reaction of a monosilane of the general formula (II) with a silane substrate comprising disilanes of the general formula (I II) derived from a Direct Process Residue, more preferably Me2SiHCI is produced in step A) in the presence of n-Bu PCI and lithium hydride by the reaction of a monosilane of the general formula (I I) with a silane substrate comprising disilanes of the general formula (III) derived from a Direct Process Residue bearing no hydrogen atoms at the silicon atoms, even more preferably Me2SiHCI is produced in step A) in the presence of n-Bu PCI and lithium hydride by the reaction of Me2SiCI2 with a silane substrate comprising disilanes of the general formula (III) based on the Direct Process Residue bearing no hydrogen atoms at the silicon atoms, and most preferably Me2SiHCI is produced in step A) in the presence of n-Bu4PCI and lithium hydride by the reaction of Me2SiCI2 with a silane substrate comprising disilanes selected from Me2CISi-SiCIMe2 and Me2CISi-SiCI2Me obtained from the Direct Process Residue.
Further preferably, in step A) MeSiHCb is produced in the presence of n-Bu PCI and lithium hydride by the reaction of a monosilane of the general formula (II) with a silane substrate comprising disilanes of the general formula (I II) derived from a Direct Process Residue, more preferably MeSiHCb is produced in step A) in the presence of n-Bu4PCI and lithium hydride by the reaction of a monosilane of the general formula (I I) with a silane substrate comprising disilanes of the general formula (II I) derived from a the Direct Process Residue bearing no hydrogen atoms at the silicon atoms, even more preferably MeSiHC is produced in step A) in the presence of n-Bu PCI and lithium hydride by the reaction of MeSiCb with a silane substrate comprising disilanes of the general formula (III) derived from a Direct Process Residue bearing no hydrogen atoms at the silicon atoms, and most preferably MeSiHCb is produced in step A) in the presence of n-Bu PCI and lithium hydride by the reaction of MeSiCb with a silane substrate comprising disilanes selected from the group of MeCbSi- SiCbMe and Me2CISi-SiCbMe derived from a Direct Process Residue.
In another preferred embodiment of the process according to the invention, in step A) Me2SiHCI is produced by the reaction of Me2SiCb in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above.
Preferably, in step A) Me2SiHCI is produced by the reaction of Me2SiCI2 with silanes selected from disilanes of the general formula (III) and carbodisilanes of the general formula (IV) having no chlorine substituents at the silicon atoms in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, more preferably Me2SiHCI is produced by the reaction of Me2SiCI2 with silanes selected from disilanes of the general formula (III) and carbodisilanes of the general formula (IV) having no chlorine substituents at the silicon atoms, wherein the molar ratio of Me2SiCI2 to silanes of the general formulae (I II) and/or (IV) having no chlorine substituents at the silicon atoms is in the range of about 99 to about 1 in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, even more preferably the molar ratio of Me2SiCI2 to silanes of the general formulae (III) and/or (IV) having no chlorine substituents at the silicon atoms is in the range of about 5 to about 1 , and most preferably the molar ratio of Me2SiCI2 to silanes of the general formulae (III) and/or (IV) having no chlorine substituents at the silicon atoms is in the range of about 3 to about 1 . Herein, the molar ratio is defined as
[n (Me2SiCI2 submitted to step A) ) / n (silanes of the general formulae (III) and/or (IV) having no chlorine substituent at the silicon atoms)]
In still another preferred embodiment of the process according to the invention, in step A) Me2SiHCI is produced by the reaction of Me2SiH2 in the presence of at least one compound of the formula R1 PCI, wherein R1 is as defined above.
Preferably, in step A) Me2SiHCI is produced by the reaction of Me2SiH2 with silanes selected from disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) having no hydrogen substituents at the silicon atoms in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, more preferably Me2SiHCI is produced by the reaction of Me2SiH2 with silanes selected from disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) having no hydrogen substituents at the silicon atoms, wherein the molar ratio of Me2SiH2 to silanes of the general formulae (III) and/or (IV) having no hydrogen substituents at the silicon atoms is in the range of about 1 to about 99 in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, even more preferably the molar ratio of Me2SiH2 to silanes of the general formulae (III) and/or (IV) having no hydrogen substituents at the silicon atoms is in the range of about 1 to about 5, and most preferably the molar ratio of Me2SiH2 to silanes of the general formulae (III) and/or (IV) having no hydrogen substituents at the silicon atoms is in the range of about 0.8 to about 1.2. Herein, the molar ratio is defined as
[n (Me2SiH2 submitted to step A) ) / n (silanes of the general formulae (III) and (IV) having no hydrogen substituents at the silicon atoms)].
In a preferred embodiment of the process according to the invention, in step A) MeSiHC is produced by the reaction of MeSiCb in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above.
Preferably, in step A) MeSiHCb is produced by the reaction of MeSiCb with silanes selected from disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) having no chlorine substituents at the silicon atoms in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, more preferably MeSiHCb is produced by the reaction of MeSiC with silanes selected from disilanes of the general formula (III) and/or carbodisilanes of the general formula (IV) having no chlorine substituents at the silicon atoms, wherein the molar ratio of MeSiCb to silanes of the general formulae (III) and/or (IV) having no chlorine substituents at the silicon atoms is in the range of about 99 to about 1 in the presence of at least one compound of the formula R1 PCI, wherein R1 is as defined above, even more preferably the molar ratio of MeSiCb to silanes of the general formulae (III) and/or (IV) having no chlorine substituents at the silicon atoms is in the range of about 5 to about 1 , and most preferably the molar ratio of MeSiCb to silanes of the general formulae (III) and/or (IV) having no chlorine substituents at the silicon atoms is in the range of about 3 to about 1 . Herein, the molar ratio is defined as
[n (MeSiCb submitted to step A) )/ n (silanes of the general formulae (I II) and/or (IV) having no chlorine substituents at the silicon atoms)].
In a preferred embodiment of the process according to the invention, in step A) MeSiHCb is produced by the reaction of MeSiH3 in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above.
Preferably, in step A) MeSiHC is produced by the reaction of MeSiH3 with silanes selected from disilanes of the general formula (I I I) and/or carbodisilanes of the general formula (IV) having no hydrogen substituents at the silicon atoms in the presence of at least one compound of the formula R14PCI, wherein R1 is as defined above, more preferably MeSiHC is produced by the reaction of MeSiH3 with silanes selected from disilanes of the general formula (I I I) and/or carbodisilanes of the general formula (IV) having no hydrogen substituents at the silicon atoms, wherein the molar ratio of MeSihh to silanes of the general formulae (I I I) and/or (IV) having no hydrogen substituents at the silicon atoms is in the range of about 1 to about 99 in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, even more preferably the molar ratio of MeSihh to silanes of the general formulae (I I I) and/or (IV) having no hydrogen substituents at the silicon atoms is in the range of about 1 to about 5, and most preferably the molar ratio of MeSihh to silanes of the general formulae (I II) and (IV) having no hydrogen substituents at the silicon atoms is in the range of about 0.8 to about 1 .2. Herein, the molar ratio is defined as
[n (MeSihh submitted to step A) )/ n (silanes of the general formulae (I II) and/or (IV) having no hydrogen substituents at the silicon atoms)].
The process of the present invention can be performed in a continuous or batch-wise manner, preferably it is carried out in a continuous manner. Therein step A) and/or B) can be performed in a continuous or batch-wise manner, preferably both steps A) and B) are performed in a continuous manner.
In another preferred embodiment of the process according to the invention, the step of separating the resulting monosilanes of the formula (I) is carried out by distillation and/or condensation.
The term "distillation" according to the present invention relates to any process for separating components or substances from a liquid mixture by selective evaporation and condensation. Therein, distillation may result in practically complete separation of the constituents of a mixture, thus leading to the isolation of nearly pure compounds, or it may be a partial separation that increases the concentration of selected constituents of the mixture in the distillate when compared to the mixture submitted to distillation.
Preferably, the distillation processes which may constitute separation step B) can be simple distillation, fractional distillation, vacuum distillation, short path distillation or any other kind of distillation known to the skilled person. Also preferably, the step B) of separating the monosilanes of the formula (I) according to the invention can comprise one or more batch distillation steps, or can comprise a continuous distillation process.
Further preferably, the term "condensation" may comprise separation or enrichment of one or more compounds of the general formula (I) from the reaction mixture by volatilization from the reaction vessel and condensation as a liquid and/or solid in a refrigerated vessel from which it can be subsequently recovered by distillation, or by solution in an ether solvent. Alternatively, the monosilanes can be absorbed in an ether solvent contained in a refrigerated vessel.
In a further preferred embodiment of the process according to the invention, the process is performed under inert conditions.
In the sense of present invention, the term "performed under inert conditions" means that the process is partially or completely carried out under the exclusion of surrounding air, in particular of moisture and oxygen. In order to exclude ambient air from the reaction mixture and the reaction products, closed reaction vessels, reduced pressure and/or inert gases, in particular nitrogen or argon, or combinations of such means may be used.
In a preferred embodiment of the invention, methylmonosilanes of the general formula (I) as defined above are obtained by the process according to any of the previous embodiments. In another preferred embodiment of the invention, compositions comprising at least one methylmonosilane of the general formula (I) as defined above are obtained by the process according to any of the previous embodiments.
Preferred embodiments of the invention
In the following the preferred embodiments of the invention are shown.
1. Process for the manufacture of monosilanes of the general formula (I):
RxSiHyClz (I),
wherein R is an organyl group,
x = 1 to 3, preferably 1 to 2,
y = 1 to 3, preferably 1 to 2,
z = 1 to 3, preferably 1 to 2, and
x + y + z = 4,
comprising:
A) the step of subjecting one or more monosilanes of the general empirical formula (II) RaSiHbCIc (II)
wherein R is as defined above,
a = 1 to 3,
b = 0 to 3,
c = 0 to 3 and
a + b + c = 4, and
to a reaction with one or more silanes selected from the group of
a) disilanes of the general empirical formula (III)
ReSi2HfClg (III)
wherein R is as defined above,
e = 1 to 5,
f = 0 to 5,
g = 0 to 5 and
e + f + g = 6,
and
b) carbodisilanes of the general empirical formula (IV) Rm(SiCH2Si)HnClo (IV)
wherein R is as defined above,
m = 1 to 5,
n = 0 to 5,
o = 0 to 5 and
m + n + o = 6
with the proviso that at least one silane of the formula (II), (III) or (IV) has at least one chlorine substituent at the silicon atom,
and wherein at least one of the silanes of the formula (II), (III) or (IV) submitted to the reaction is selected from the group consisting of:
a monosilane of the general formula (I I) with c = 0,
a disilane of the general formula (III) with g = 0, or
a carbodisilane of the general formula (IV) with o = 0,
in the presence of one or more compounds (C) selected from the group of:
- R1 4PCI, wherein R1 is selected from the group consisting of hydrogen and an organyl group, which can be the same or different, more preferably R1 is selected from the group consisting of an aromatic group and an aliphatic hydrocarbon group, even more preferably a n-alkyl group, and most preferably a n-butyl group,
- phosphines R13P, wherein R1 is selected from the group consisting of hydrogen and an organyl group and can be the same or different, preferably R3P, wherein R is as defined above and can be the same or different, such as preferably PPh3,
- amines R13N , wherein R1 is selected from the group consisting of hydrogen or an organyl group and can be the same or different, preferably R3N, wherein R is as defined above and can be the same or different, such as preferably n-Bu3N,
- N-heterocyclic amines, preferably methylimidazoles, such as 2-methylimidazole, 4- methylimidazole and 1 - methylimidazole, and
- ammonium compounds, such as R1 4NCI, wherein R1 is selected from the group consisting of hydrogen and an organyl group and can be the same or different, preferably R4NCI, wherein R is as defined above and can be the same or different, such as preferably n- Bu4NCI, and
B) optionally a step of separating the resulting monosilanes of the general formula (I). 2. The process according to embodiment 1 , wherein step A) is carried out in the presence of one or more, preferably one organic solvent, preferably an high-boiling ether compound, more preferably 1 ,4-dioxane, diglyme or tetraglyme, most preferably diglyme.
3. The process according to embodiments 1 or 2, wherein step A) is carried out in the presence of one or more hydride donors, preferably one or more metal hydrides, more preferably one or more metal hydrides selected from the group of alkali metal hydrides and alkaline earth metal hydrides, and most preferably lithium hydride.
4. The process according to any of the previous embodiments, wherein in general formula (I) and one or more of the general formulae (II), (I II) or (IV) R is an alkyl or cycloalkyl group, preferably a methyl group.
5. The process according to any of the previous embodiments, wherein the silanes of the formulae (II), (II I) or (IV) submitted to the reaction comprise one or more silanes selected from the group consisting of
monosilanes of the general formula (II) with b = 0,
disilanes of the general formula (III) with f = 0, and
carbodisilanes of the general formula (IV) with n = 0.
6. The process according to any of the previous embodiments, wherein for all monosilanes of the general formula (II) subjected to the reaction in step A) c = 0.
7. The process according to any of the embodiments 1 to 5, wherein for all monosilanes of the general formula (II) subjected to the reaction in step A) b = 0.
8. The process according to any of the embodiments 1 to 6, wherein for all monosilanes of the general formula (I I) subjected to the reaction in step A) c = 0, and wherein for all disilanes of the general formula (I II) f = 0 and for all carbodisilanes of the general formula (IV) n = 0.
9. The process according to the any of the embodiments 1 to 5 and 7, wherein for all monosilanes of the general formula (II) subjected to the reaction in step A) b = 0, and wherein for all disilanes of the general formula (II I) g = 0 and for all carbodisilanes of the general formula (IV) o = 0.
10. The process according to any of the previous embodiments, wherein silane substrates of the general formulae (II), (III) or (IV) having one or more hydrogen substituents at the silicon atom(s) in step A) are prepared by a hydrogenation reaction prior to step A).
1 1 . The process according to any of the embodiments 3 to 10, wherein the amount of the metal hydride in step A) in relation to the silane substrate compounds is in the range of about 0.05 mol-% to about 395.95 mol-%, preferably about 20 mol-% to about 200 mol-%, more preferably about 50 mol-% to about 150 mol-%, and most preferably about 80 mol-% to about 100 mol-%.
12. The process according to any of the previous embodiments, wherein the amount of the one or more compounds (C) in step A) in relation to the silane substrate compounds is in the range of about 0.0001 mol-% to about 600 mol-%, more preferably about 0.01 mol-% to about 20 mol-%, even more preferably about 0.05 mol-% to about 2 mol-%, and most preferably about 0.05 mol-% to about 1 mol-%.
13. The process according to any of the embodiments 2 to 12, wherein in the step A) the weight ratio of the silane substrates to the organic solvent is in the range of about 0.01 to about 100, preferably in the range of about 0.1 to about 10, more preferably about 0.5 to about 4, most preferably about 0.5 to about 1 .
14. The process according to any of the previous embodiments, wherein the step A) is conducted at a temperature of about 0 °C to about 300 °C, preferably about 20 °C to about 250 °C, more preferably about 80 °C to about 220 °C.
15. The process according to any of the previous embodiments, wherein the step A) is conducted at a pressure of about 0.1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
16. The process according to any of the previous embodiments, wherein the monosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSiHC and
MeSihbCI.
17. The process according to any of the previous embodiments, wherein the silanes of the general formula (II) are selected from the group consisting of Me2SiCI2, MeSiC , Me2SiH2 and MeSih .
18. The process according to the previous embodiments, wherein the silanes of the general formulae (III) are selected from the group of MeH2Si-SiH2Me, MeH2Si-SiHMe2, Me2HSi-SiHMe2, MeC Si-SiC Me, MeCI2Si-SiCIMe2 and Me2CISi-SiCIMe2.
19. The process according to any previous embodiments, wherein the carbodisilanes of the general formula (IV) are selected from the group consisting of MeH2(SiCH2Si)H2Me, MeH2(SiCH2Si)HMe2, Me2H(SiCH2Si)HMe2, MeCI2(SiCH2Si)CI2Me, MeCI2(SiCH2Si)CIMe2 and Me2CI(SiCH2Si)CIMe2.
20. The process according to the previous embodiments, wherein step A) is carried out in the presence of at least one compound of the formula R\PCI, wherein R1 is as defined above. 21 . The process according to the previous embodiment, wherein the compounds of formula R\PCI are formed in situ from compounds of the formulae R1 3P and R1CI, wherein R1 is as defined above, preferably R1 is R as defined above.
22. The process according to any of the previous embodiments, wherein step A) is carried out in the presence of at least one compound of the formula R14PCI and lithium hydride.
23. The process according to any of the previous embodiments, wherein step A) is carried out in the presence of n-Bu PCI.
24. The process according to any of the previous embodiments, wherein step A) is carried out in the presence of n-Bu PCI and lithium hydride.
25. The process according to any of the embodiments 1 to 5, 7 and 9 to 24, wherein in step A) Me2SiHCI is produced by the reaction of Me2SiCI2 in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above.
26. The process according to any of the embodiments 1 to 6, 8 and 10 to 24, wherein in step A) Me2SiHCI is produced by the reaction of Me2SiH2 in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above.
27. The process according to any of the embodiments 1 to 5, 7 and 9 to 24, wherein in step A) MeSiHC is produced by the reaction of MeSiC in the presence of at least one compound of the formula R1 PCI, wherein R1 is as defined above.
28. The process according to any of the embodiments 1 to 6, 8 and 10 to 24, wherein in step A) MeSiHCb is produced by the reaction of MeSihh in the presence of at least one compound of the formula R1 PCI, wherein R1 is as defined above.
29. The process according to any of the previous embodiments, wherein the step of separating the resulting monosilanes of the formula (I) is carried out by distillation and/or condensation.
30. The process according to any of the previous embodiments, wherein the process is performed under inert conditions.
31 . Methylmonosilanes of the general formula (I) as defined above, and mixtures thereof, as obtainable by the process according to any of the previous embodiments.
32. Compositions comprising at least one methylmonosilane of the general formula (I) as defined above, as obtainable by the process according to any of the embodiments 1 to 31 .
33. The process according to the present invention, which is carried out in a continuous or batch-wise manner, preferably in a continuous manner. Therein step A) and/or B) can be performed in a continuous or batch-wise manner, preferably both steps A) and B) are performed in a continuous manner.
EXAMPLES
The present invention is further illustrated by the following examples, without being limited thereto.
General
Prior to the reactions the metal salts as well as the solvents used were carefully dried according to procedures known from the literature. The reactions investigated were generally performed in sealed NMR tubes first to prevent evaporation of low boiling reaction products, such as hydrogenated organomonosilanes, and to elucidate the reaction conditions (temperature, time) for the performed reactions. Subsequently, these conditions were exemplarily transferred onto cleavage reactions in a preparative scale in a closed system, preferably a sealed glass ampoule to avoid evaporation of low boiling reaction educts and products, e.g. organochloro- and organohydridosilanes. After the reaction was completed, the ampoule was frozen, opened under vacuum and products formed were isolated by combined condensation/distillation procedures. Products were analyzed and characterized by standard procedures, especially by NMR spectroscopy and GC/MS analyses.
Identification of products
Products were analyzed by 1 H, 29Si and 1 H-29Si-HSQC NMR spectroscopy. The spectra were recorded on a Bruker AV-500 spectrometer equipped with a Prodigy BBO 500 S1 probe. 1 H- NMR spectra were calibrated to the residual solvent proton resonance ([D6]benzene <5H = 7.16 ppm). Product identification was additionally supported by GC-MS analyses and verified identification of the main products. GC-MS analyses were measured with a Thermo Scientific Trace GC Ultra coupled with an ITQ 900MS mass spectrometer. The stationary phase (Macherey-Nagel PERMABOND Silane) had a length of 50 m with an inner diameter of 0.32 mm. 1 μΙ of analyte solution was injected, 1/25 thereof was transferred onto the column with a flow rate of 1 .7 mL/min carried by Helium gas. The temperature of the column was first kept at 50 °C for 10 minutes. Temperature was then elevated at a rate of 20 °C/min up to 250 °C and held at that temperature for another 40 minutes. After exiting the column, substances were ionized with 70 eV and cationic fragments were measured within a range of 34 - 600 m/z (mass per charge) . Product mixtures were diluted with benzene prior to the measurement.
The characteristic 29Si-NMR chemical shifts and coupling constants J{29Si-1 H} for compounds I to XXX are listed in Table 1 . Table 1
Figure imgf000041_0001
Example 1 :
MehbSi-SihbMe (VIII, 0.8 mmol) and MeSiC (1.3 mmol) were mixed with a catalytic amount of the redistribution catalyst of n-Bu4PCI (0.02 mmol) in diglyme (0.35 ml) as solvent in an NMR tube, solidified at -196 °C (liquid nitrogen) and sealed in vacuo. After warming the samples to r.t., 29Si- and 1H-NMR spectra were measured to prove the degree of SiH/SiCI redistributions after different reaction times and temperatures to control and quantify product formation by integration of the intensity of relevant NMR signals within the mixture. As displayed in Table 2 already after 14 h at 80 °C chlorosilane IV was nearly completely consumed to give nearly equimolar amounts of the target compounds V and VI (41 % vs. 42%). Taking the formation of hydridosilane VII (16%) into consideration, silicon-silicon bond cleavage, hydrogenation and subsequent redistribution reactions occurred quantitatively. Increasing the reaction temperature and time to 120 °C/42 h did not shift the redistribution equilibrium significantly. Table 2
Figure imgf000042_0001
Example 2:
The experiment was conducted in analogy to Example 1 , but in contrast to Example 1 the molar amount of dimethyldisilane VIII was reduced to half of the original amount (0.4 mmol), while methyltrichlorosilane IV was used in excess (1.7 mmol). Disilane cleavage and redistribution started already at r.t. giving nearly equimolar amounts of the target compounds V and VI. With longer reaction times, the relative amount of compound VI was strongly increased by chlorination of methylsilane VII and methylchlorosilane V. At 80 °C, the molar ratio of silanes V/VI was 12.2/68.5, demonstrating targeted product formation by control of the reaction conditions. Increasing the reaction temperature to 120 °C (19 h) supported further redistribution of compounds IV and V to give MeSiHCh VI in 73% yield. The results are displayed in Table 3. Table 3
Figure imgf000042_0002
Example 3:
In the experiment the same solvent, catalyst and reaction vessel as in Example 1 was used, but the mixture of dimethyltetrachlorodisilane (XIII, 1.1 mmol) and methylsilane (VII, 0.7 mmol) already reacted at r.t. to give a mixture with a complex product distribution: the target compound V was formed in a molar amount of 41 %, with 26% of methyldichlorosilane, and the starting compound VII was already consumed nearly quantitatively (3.4% remaining). After 38 h at room temperature (r.t.), the molar amount of compound V was drastically reduced to 22% while that of dichlorosilane VI was increased to 65%. All disilanes IX to XII, formed as intermediates by H/CI-exchange (redistribution) on the disilane skeleton within 2 h at r.t., were completely cleaved at longer reaction times, only traces of IX and starting disilane XIII remained. After additional 4 h at 80 °C disilane cleavage was completed to give the most valuable products V and VI in about 90% yield. Targeted product formation is easily controlled by the reaction conditions. The 29Si-NMR spectrum, measured after additional 19 h reaction time at 120 °C, convincingly showed that the redistribution equilibrium was reached already after additional 4 h at 80 °C. The results are displayed in Table 4.
Table 4
Figure imgf000043_0001
Example 4:
MeH2Si-SiH2Me (VIII, 0.5 mmol), MeSiCb (IV, 1.7 mmol), diglyme (0.35 ml) and a catalytical amount of n-Bu4NCI (0.02 mmol) were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. After 7 days reaction time at r.t., disilane VIII was cleaved quantitatively to form methylsilane VII that subsequently redistributed with MeSiCb IV to give the target products V and VI in 28% and 59% yield, respectively (Table 5). Prolonged reaction times and temperatures (120 °C/ additional 34 h) did not shift the redistribution equilibrium significantly.
Table 5
Figure imgf000043_0002
Example 5:
The reaction was performed in an analogous manner to the reaction of Example 4, using tetramethyldisilane (XIV, 0.6 mmol), Me2SiCI2 (II, 1.2 mmol), diglyme (0.35 ml) and a catalytic amount of n-Bu4PCI (0.02 mmol). After 14 hours at 80 °C, the targeted product Me2SiHCI III was formed in 47% yield. The starting disilane was chlorinated to give disilane XV in 12% yield, methylhydridochlorodisilane XVI was formed in 7% yield, both disilanes were formed by redistribution at the disilane skeleton (Table 6). Increasing the reaction temperature to 120 °C for additional 42 h shifted the redistribution equilibrium negligibly but led to the formation of a small amount of trisilanes (1 mol%). Table 6
Figure imgf000044_0001
Example 6:
Tetramethyldichlorodisilane (XV, 1 .1 mmol), Me2SiH2 (I, 0.8 mmol), diglyme (0.35 ml) and n- Bu4PCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. The starting materials reacted already at r.t. to give 38.5% of Me2SiHCI I II , the relative molar amount of tetramethylchlorohydridodisilane XVI was about 22%. Heating the mixture to 80 °C (4 h) shifted the cleavage/redistribution equilibria only slightly. Additional 19 h reaction time at 120 °C further decreased the amount of disilanes XVI and XV, increased the amount of monosilanes I and II and led to the formation of trisilanes (2 mol%) (Table 7).
Table 7
Figure imgf000044_0002
Example 7:
Tetramethyldisilane (XIV, 0.6 mmol), Me2SiCI2 (II, 1 .2 mmol), diglyme (0.35 ml) and n-Bu4NCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. After 7 days of reaction time at r.t. , the starting disilane was chlorinated to give 2% of disilane XV, methylhydridochlorodisilane XVI was formed in a molar amount of 16.4%; both disilanes were formed by redistribution at the disilane skeleton. Si-Si bond cleavage of tetramethyldisilane XIV and subsequent redistribution of formed Me2SiH2 with chlorosilanes gave compound III in 9.6% yield. After additional 34 h reaction time at 120 °C, dimethyldichlorosilane II was reduced to form the targeted Me2SiHCI III in 45% yield, while tetramethyldisilane XIV was further chlorinated to give 1 1 % of disilane XV (Table 8). Table 8
Figure imgf000045_0001
Example 8:
Equimolar amounts of dimethyltetrachlorodisilane (XIII, 0.6 mmol), Me2SiH2 (I, 0.6 mmol), diglyme (0.35 ml) and n-Bu4PCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. Already at r.t. 38% of compound III was formed, dichlorosilane VI in 6.4% yield, and it remained 12.4% of disilane XIII. Increasing the reaction time by 36 h yielded the target compounds III and VI in about 46% and 37%, including the formation of V (3.7%). the overall yield of Si-H formation was >86%. Increasing the reaction temperature to 80 °C led to an increase of the relative molar amount of compound VI by a simultaneous decrease of compound III (to 37.3%). At 120 °C (additional 19 h), the compound Me2SiHCI III was nearly completely decomposed (4.7%) obviously being chlorinated to give dichlorosilane II (6%→ 29%) while compound IV was hydrogenated to compounds V and VI (Table 9). As discussed earlier, targeted product formation was strongly controlled by the reaction conditions, providing a variety of technical options to produce the most valuable hydridochlorosilanes starting from isolated raw materials of the Mtiller Rochow Direct Process (monosilanes) and the isolated disilanes of the Direct Process Residue (DPR).
Table 9
Figure imgf000045_0002
Example 9:
Tetramethyldichlorodisilane (XV, 1.1 mmol), methylsilane (VII, 0.8 mmol), diglyme (0.35 ml) and n-Bu4PCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to - 196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. Chlorosilane III was not formed at r.t. even after 36 hours, while monosilanes V and VI were produced in a molar amount of about 23% (Table 10). Warming the mixture to 80 °C (for additional 4 hours) started the formation of Me2SiHCI (14%), and simultaneously the molar amounts of compounds V (14%) and VI (1.5%) diminished. After additional 19 h reaction time at 120 °C, disilanes XVI and XV were completely cleaved, while the target product Me2SiHCI III was formed in 61.6% yield.
Table 10
Figure imgf000046_0001
Example 10
Dimethyldisilane (VIII, 0.4 mmol), excess Me2SiCI2 (II, 1.6 mmol), diglyme (0.35 ml) and n- Bu4PCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. Already at room temperature, III and V were formed in 8.8% and 7.0%, respectively. Starting disilane VIII was completely cleaved, mainly to yield MeSiH3 (VII, 22%). Longer reaction times as well as warming the mixture increased the relative molar amounts of the target compounds (at 80 °C/+4 h, all compounds lll-VI obtained in a yield greater than 47%; at 120 °C/+19 h, all compounds lll-VI obtained in 53% yield). Related to the amount of MeSiH3 VII and excess of compound II, the product formation was nearly quantitative. The results are displayed in Table 1 1.
Table 11
Figure imgf000046_0002
Example 11
Tetramethyldisilane (XIV, 0.3 mmol), excess MeSiC (IV, 1.7 mmol), diglyme (0.35 ml) and n-Bu4PCI (0.02 mmol) as catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. Me2SiHCI III was not detected at r.t. but the disilane was chlorinated to give disilane XV (12%). Reduction of MeSiC (H-transfer from disilane XIV) yielded V in small amounts (1.2%) while target product VI was formed in nearly 40% yield (80 °C/+4 h). At 120 °C (additional 19 h) disilane XV was reduced by about a half (1 1.9% → 6.7%) to form dimethyldichlorosilane II in 13.8% yield. The catalyst remained unreacted as shown by 31P-NMR spectroscopy. The results are displayed in Table 12.
Table 12
Figure imgf000047_0002
Example 12
9.60 g of a complex mixture of mono-, di- and carbodisilanes (45.90 mmol, the silane distribution is listed in Table 13), 3.27 g (54.35 mmol) Me2SiH2, 0.18g (0.61 mmol) n-Bu4PCI, 1.5 ml C6D6 and 8 ml diglyme were placed in a -196 °C cooled ampoule with an attached NMR tube, the ampoule was evacuated and sealed. After 136 h at 80 °C, 0.6 ml of the product mixture was poured from the ampoule into the attached NMR tube, which was then sealed and disconnected from the ampoule. NMR spectroscopic measurements revealed a product distribution listed in Table 14.
Table 13
Figure imgf000047_0003
Figure imgf000047_0001
As listed in Table 14, methylchlorodisilanes were cleaved almost quantitatively (1.4% remained), while monosilanes III to VII were formed in 62% yield.
Example 13
9.60 g of a complex mixture of mono-, di- and carbodisilanes (45.90 mmol, silane distribution is listed in Table 13), 1.22 g (26.44 mmol) MeSihh, 0.25g (0.85 mmol) n-Bu4PCI, 1.5 ml C6D6 and 8 ml diglyme were placed in a -196 °C cooled ampoule with an attached NMR tube, the ampoule was evacuated and sealed. After 136 h at 80 °C, 0.6 ml of the product mixture was poured from the ampoule into the attached NMR tube, which was then sealed and disconnected from the ampoule. NMR spectroscopic measurements revealed a product distribution listed in Table 15.
Table 15
Figure imgf000048_0001
As can be seen from Table 15, methylchlorodisilanes were cleaved almost quantitatively (2.4% remained), while monosilanes III to VI were formed in >71 % yield. It remained 6% of MeSihh in the mixture.
Examples 12 and 13 clearly demonstrate the potential to produce the most valuable methylhydridochlorosilanes starting from formerly isolated raw materials of the Mtiller Rochow Direct Process (monosilanes) and the formerly isolated disilane from the Direct Process Residue (DPR).
Example 14
A complex mixture of methylchlorocarbodisilanes (0.5 mmol, carbodisilane distribution is listed in Table 16), Me2SiH2 (I, 1.4 mmol), diglyme (0.35 ml) and n-Bu4PCI (0.02 mmol) as redistribution catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. At 80 °C (25 h) dimethylsilane I was chlorinated to form compound III in 52% yield, while the methylchlorocarbodisilanes were hydrogenated. In relation to the starting amount of Me2SiH2 II, 61 % have been converted into the targeted product III. Increasing the reaction temperature to 120 °C (additional 28 h) did not shift the redistribution equilibrium significantly (Table 17). The catalyst n-Bu4PCI was not decomposed as shown by 31P-NMR spectroscopy.
Table 16
Figure imgf000049_0001
Table 17
Figure imgf000049_0002
Example 15
In analogy to Example 14, a complex mixture of methylchlorocarbodisilanes (1.0 mmol, Table 16) reacted with MeSiH3 VII (0.55 mmol) in diglyme (0.35 ml) under phosphonium chloride (n-Bu4PCI) (0.2 mmol) catalysis. At 80 °C (25 h) methylsilane MeSiH3 was chlorinated to form MeSiH2CI V and MeSiHCI2 VI in molar amounts of 37% and 15%, respectively, while the methylchlorocarbodisilanes were hydrogenated. In relation to the starting amount of MeSiH3 VII, 70% were converted into the target compounds V and VI. Increasing the reaction temperature to 120 °C (additional 28 h) did not shift the redistribution equilibrium but led to the formation of Me2SiCI2 II in small amounts (2%), obviously due to cleavage of carbodisilanes (Table 18). Again, the catalyst n-Bu4PCI remained unreacted as shown by NMR 31P.
Table 18
Figure imgf000049_0003
Example 16
Carbodisilane (HMe2Si)2CI-l2 (XXVI I I , 0.3 mmol), Me2SiCI2 (I I , 1 .7 mmol) , diglyme (0.35 ml) and n-BmPCI (0.04 mmol) as redistribution catalyst were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen) . After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NMR spectroscopy. As displayed in Table 19, Cl/H redistribution at the silicon atom was not observed at r.t. after 72 h, but heating the sample to 220 °C for additional 6 hours finally led to the formation of Me2SiHCI I I I in a molar amount of 5% and the chlorinated carbodisilane XXVI I in a molar amount of 2%.
Table 19
Figure imgf000050_0001
Example 17
In analogy to Example 16, (HMe2Si)2CH2 (XXVI I I , 0.3 mmol) was reacted with MeSiC (IV, 1 .7 mmol) in diglyme (0.35 ml) under phosphonium chloride (n-Bu4PCI) (0.05 mmol) catalysis in an NMR tube. After 72 h reaction time at r.t. methyltrichlorosilane IV was reduced to give MeSiHCI2 in 8% yield, while compound XXVI I I was chlorinated to give (CIMe2Si)2CH2 XXVI I in 3% yield. Heating the reaction mixture to 220 °C (additional 6 h) led to the chlorination of compound XXVI I I quantitatively into compound XXVI I under formation of the targeted product VI in 13% yield (Table 20) .
Table 20
Figure imgf000050_0002
Example 18
A complex mixture of methylhydridocarbodisilanes (0.2 mmol, carbodisilane distribution in the mixture is listed in Table 21 ), Me2SiCI2 (I I , 1 .5 mmol), diglyme (0.35 ml) and n-Bu4PCI (0.05 mmol) as redistribution catalyst were placed in an NMR tube that was cooled to - 196 °C (liquid nitrogen) . After evacuation in vacuo the NMR tube was sealed, warmed to r.t. and the reaction course was monitored by NM R spectroscopy at different temperatures. Already at r.t. (72 hours), the targeted product I I I was formed by Cl/H redistribution in 42% yield as well as dimethylsilane in 7% yield. With prolonged reaction times at higher temperatures (80 °C/+6 h and 120 °C/+8 h) the amount of Me2SiHCI I I I increased to 52% , while the amount of dimethylsilane and dimethyldichlorosilane decreased (I : 7%→ 5% , I I : 41 %→ 33%) (Table 22) . Table 21
Figure imgf000051_0001
Table 22
Figure imgf000051_0002
Example 19
In an experiment similar to Example 18 the amount of methylhydridocarbodisilanes was decreased to one half of the original amount (0.1 mmol, carbodisilane distribution is listed in Table 21) and reacted with Me2SiCl2 (II, 1.5 mmol) under comparable conditions, giving analogous results (Table 23).
Table 23
Figure imgf000051_0003
In both Examples 18 and 19 not all carbodisilanes were fully chlorinated, although Me2SiCl2 was used in excess. Example 20
A complex mixture of methylhydridocarbodisilanes (0.2 mmol, carbodisilane distribution is listed in Table 21) reacted with MeSiC (IV, 1.6 mmol) in diglyme (0.35 mmol) under phosphonium chloride (n-Bu4PCI) (0.05 mmol) catalysis in an NMR tube at different temperatures. Already at r.t. (72 h), the redistribution reaction occurred quantitatively to give the targeted products MeSiHC VI and MeSiH2CI V in 64% and 12% yield, respectively. These reaction conditions are more in the favor of the formation of MeSiHCI2. In contrast to Examples 18 and 19, all methylcarbodisilanes were fully chlorinated. Increasing the reaction temperatures and reaction times to 80 °C/+6 h and 120 °C/+8 h did not shift the redistribution equilibrium significantly (Table 24). Table 24
Figure imgf000052_0001
Example 21
In an experiment similar to Example 20, the amount of methylhydridocarbodisilanes was decreased to one half of the original amount (0.1 mmol, carbodisilane distribution is listed in Table 21) and reacted with MeSiC (IV, 1 .6 mmol) under comparable conditions. Again, already at r.t. (72 h) the redistribution reaction occurred quantitatively. MeSiHC VI was formed selectively in 32% yield, while the carbodisilanes were fully chlorinated. Increasing the reaction temperatures and times to 80 °C/+6 h and 120 °C/+8 h did again not shift the redistribution equilibrium (Table 25).
Table 25
Figure imgf000052_0002
The redistribution reactions in Examples 19 and 20 occurred faster and quantitatively under mild conditions, obviously due to the higher H-affinity of MeSiCb compared to Me2SiCI2. Examples 18 to 21 clearly demonstrate that targeted products can selectively be formed depending on reaction conditions, thus making product formation controllable. Again, in all experiments the catalyst remained intact as shown by 31 P NMR.
Example 22:
LiH (3.7 mmol), MeSiCb (0.9 mmol), MeC Si-SiC Me (0.9 mmol), diglyme (0.4 ml) and catalytic amounts of n-Bu4PCI (0.04 mmol) were placed in an NMR tube cooled to -196 °C (liquid nitrogen). After evacuation the NMR tube was sealed, warmed and investigated by NMR spectroscopy.
Table 26
Figure imgf000052_0003
Already at 120 °C/13 h, MeCI2Si-SiCI2Me was hydrogenated, quantitatively cleaved and redistributed with monosilanes to give the targeted products VI and V in molar amounts of 64% and 10%, respectively. Prolonged reaction times at 160 °C increased the amount of compound V (24%), while 3% of MeSiH3 VII were formed (Table 26).
Example 23
The reaction was performed in an analogous manner to the reaction of Example 22 using Me2SiCI2 (0.8 mmol), Me2CISi-SiCIMe2 (0.8 mmol), LiH (2.5 mmol), diglyme (0.4 ml) and catalytic amounts of n-Bu4PCI (0.04 mmol).
Table 27
Figure imgf000053_0002
At 120 °C/13 h Me2CISi-SiCIMe2 was cleaved as well as partially and fully hydrogenated to give compounds XIV and XVI in 4% and 17% yield. Targeted product Me2SiHCI III was formed in 44% yield besides Me2SiH2 in 17% yiled. Prolonged reaction times (+22 h) led to further hydrogenation by LiH to give compound I in 35% yield, while targeted product III was reduced to 42%. The amount of disilanes XV and XVI decreased to 1 % and 5%, respectively, while the amount of the fully hydrogenated disilane XIV increased slightly (6%). Trisilanes were formed in a molar amount of 5% (Table 27).
Example 24
Me2HSi-SiHMe2 (0.3 mmol), Me2SiCI2 (0.8 mmol), diglyme (0.4 ml) and a catalytic amount of PPh3 (0.05 mmol) were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed and warmed to r.t.. The starting materials reacted upon heating the sample, and the reaction course of the chlorosilane reduction/redistribution reaction was monitored by NMR spectroscopy.
Table 28
Figure imgf000053_0001
At 220 °C/+15 h dimethyldichlorosilane was hydrogenated to give Me2SiHCI III and Me2SiH2 I in 7% and 2% yield, respectively, while starting hydridodisilane XIV was chlorinated to give the partially chlorinated disilane XVI in 5% yield as well as the fully chlorinated disilane XV in 1 %. The results are displayed in Table 28.
Example 25
The reaction was performed in an analogous manner to the reaction of Example 24 using MeC Si-SiC Me (0.6 mmol), MeSiC (0.6 mmol), LiH (1.5 mmol), diglyme (0.4 ml) and PPh3 (0.05 mmol) as redistribution catalyst.
Table 29
Figure imgf000054_0001
After 16 h at 160 °C, the starting material disilane MeCI2Si-SiCI2Me was quantitatively cleaved and via redistribution reactions the targeted products MeSiHCb VI and MeSiH2CI V were formed in 50% and 8% yield, respectively. With prolonged reaction times (15 h) at 220 °C, the molar amounts of compounds VI and V were further increased to 56% and 1 1%, while non-identified products were formed in 4% yield. The results are displayed in Table 29.
Example 26
0.6 mmol of a complex mixture of chlorocarbodisilanes (carbodisilane distribution is listed in Table 30), Me2SiCI2 (0.8 mmol), LiH (1.6 mmol), n-Bu3P (0.05 mmol) and diglyme (0.3 ml) were placed in a cooled NMR tube (-196 °C). After evacuation in vacuo the NMR tube was sealed and warmed to r.t.. The starting materials reacted upon heating the sample, and the reaction course of the chlorosilane reduction/redistribution reaction was monitored by NMR spectroscopy.
Table 30
Figure imgf000054_0002
Table 31
Figure imgf000055_0001
After 16 h at 160 °C, the targeted product Me2SiHCI I I I as well as dimethylsilane were formed in 8% and 34% yield, respectively. Hydrogenation and cleavage of chlorocarbodisilanes gave 2% of methylsilane VI I . With prolonged reaction times (+ 15 h) at 220 °C the molar amount of compound I II increased to 34% , while that of Me2SiH2 I decreased (5%) due to redistribution reactions with chlorosilanes. Carbodisilanes were further cleaved (13% remained) to give silanes VI , V and VI I in 7%, 7% and 9% yield, respectively (Table 31 ) .
Example 27
0.8 mmol of a complex mixture of hydridocarbodisilanes (carbodisilane distribution is listed in Table 32), Me2SiCI2 (0.8 mmol) , n-Bu3P (0.05 mmol) and diglyme (0.35 ml) were placed in a cooled NMR tube (- 196 °C). After evacuation in vacuo the NMR tube was sealed and warmed to r.t. The starting materials reacted upon heating the sample, and the reaction course of the chlorosilane reduction/redistribution reaction was monitored by NMR spectroscopy.
Table 32
Figure imgf000055_0002
Table 33
Figure imgf000055_0003
After 16 h at 160 °C, the targeted product Me2SiHCI III was formed only in 2% yield. Increasing the reaction temperature to 220 °C for additional 15 hours gave 29% of compound III as well as 20% of dimethylsilane. The molar amount of carbodisilanes decreased from 51 % to 1 1% to give MeSiHC VI, MeSiH2CI V and MeSih VII in 10%, 3% and 24% yield, respectively (Table 33).
Example 28
MeH2Si-SiH2Me (VIII, 1.1 mmol), MeCI2Si-SiCI2Me (XIII, 1.1 mmol), diglyme (0.35 ml) and a catalytic amount of n-Bu3P (0.05 mmol) were placed in an NMR tube that was cooled to -196 °C (liquid nitrogen). After evacuation in vacuo the NMR tube was sealed and warmed to r.t.. The starting materials reacted upon heating the sample, and the reaction course of the chlorosilane reduction/redistribution reaction was monitored by NMR spectroscopy.
Table 34
Figure imgf000056_0001
After 10 hours at 220 °C, the starting disilanes VIII and XIII were quanitatively cleaved to g the targeted products VI and V in 51 % and 31 % yield, respectively, as well methyltrichlorosilane IV and methylsilane VII in 7% and 9% yield, respectively (Table 34).

Claims

1. Process for the manufacture of monosilanes of the general formula (I):
RxSlHyClz (I),
wherein R is an organyl group,
x = 1 to 3, preferably 1 to 2,
y = 1 to 3, preferably 1 to 2,
z = 1 to 3, preferably 1 to 2, and
x + y + z = 4,
comprising:
A) the step of subjecting one or more monosilanes of the general empirical formula (II)
RaSiHbCIc (II)
wherein R is as defined above,
a = 1 to 3,
b = 0 to 3,
c = 0 to 3 and
a + b + c = 4, and
to a reaction with one or more silanes selected from the group of
a) disilanes of the general empirical formula (III)
ReSi2HfClg (III)
wherein R is as defined above,
e = 1 to 5,
f = 0 to 5,
g = 0 to 5 and
e + f + g = 6,
and
b) carbodisilanes of the general empirical formula (IV)
Rm(SiCH2Si)HnClo (IV) wherein R is as defined above,
m = 1 to 5,
n = 0 to 5,
o = 0 to 5 and
m + n + o = 6
with the proviso that at least one silane of the formula (II), (III) or (IV) has at least one chlorine substituent at the silicon atom,
and wherein at least one of the silanes of the formula (II), (III) or (IV) submitted to the reaction is selected from the group consisting of:
a monosilane of the general formula (I I) with c = 0,
a disilane of the general formula (III) with g = 0, or
a carbodisilane of the general formula (IV) with o = 0,
in the presence of one or more compounds (C) selected from the group of:
- R1 4PCI, wherein R1 is selected from the group consisting of hydrogen and an organyl group, which can be the same or different, more preferably R1 is selected from the group consisting of an aromatic group and an aliphatic hydrocarbon group, even more preferably a n-alkyl group, and most preferably a n-butyl group,
- phosphines R1 3P, wherein R1 is selected from the group consisting of hydrogen and an organyl group and can be the same or different, preferably R3P, wherein R is as defined above and can be the same or different, such as preferably PPh3,
- amines R1 3N, wherein R1 is selected from the group consisting of hydrogen or an organyl group and can be the same or different, preferably R3N, wherein R is as defined above and can be the same or different, such as preferably n-Bu3N,
- N-heterocyclic amines, preferably methylimidazoles, such as 2-methylimidazole, 4- methylimidazole and 1 - methylimidazole, and
- ammonium compounds, such as R1 4NCI, wherein R1 is selected from the group consisting of hydrogen and an organyl group and can be the same or different, preferably R4NCI, wherein R is as defined above and can be the same or different, such as preferably n- Bu4NCI, and
B) optionally a step of separating the resulting monosilanes of the general formula (I).
2. The process according to claim 1 , wherein step A) is carried out in the presence of one or more, preferably one organic solvent, preferably an high-boiling ether compound, more preferably 1 ,4-dioxane, diglyme or tetraglyme, most preferably diglyme.
3. The process according to claims 1 or 2, wherein step A) is carried out in the presence of one or more hydride donors, preferably one or more metal hydrides, more preferably one or more metal hydrides selected from the group of alkali metal hydrides and alkaline earth metal hydrides, and most preferably lithium hydride.
4. The process according to any of the previous claims, wherein in general formula (I) and one or more of the general formulae (II), (III) or (IV) R is an alkyl or cycloalkyl group, preferably a methyl group.
5. The process according to any of the previous claims, wherein the silanes of the formulae (II), (III) or (IV) submitted to the reaction comprise one or more silanes selected from the group consisting of
monosilanes of the general formula (II) with b = 0,
disilanes of the general formula (III) with f = 0, and
carbodisilanes of the general formula (IV) with n = 0.
6. The process according to any of the previous claims, wherein for all monosilanes of the general formula (II) subjected to the reaction in step A) c = 0.
7. The process according to any of the claims 1 to 5, wherein for all monosilanes of the general formula (II) subjected to the reaction in step A) b = 0.
8. The process according to any of the claims 1 to 6, wherein for all monosilanes of the general formula (II) subjected to the reaction in step A) c = 0, and wherein for all disilanes of the general formula (III) f = 0 and for all carbodisilanes of the general formula (IV) n = 0.
9. The process according to the any of the claims 1 to 5 and 7, wherein for all monosilanes of the general formula (II) subjected to the reaction in step A) b = 0, and wherein for all disilanes of the general formula (II I) g = 0 and for all carbodisilanes of the general formula (IV) o = 0.
10. The process according to any of the previous claims, wherein the step A) is conducted at a temperature of about 0 °C to about 300 °C, preferably about 20 °C to about 250 °C, more preferably about 80 °C to about 220 °C.
1 1 . The process according to any of the previous claims, wherein the monosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSiHC and MeSiH2CI.
12. The process according to any of the previous claims, wherein the silanes of the general formula (II) are selected from the group consisting of Me2SiCI2, MeSiC , Me2SiH2 and MeSih , and/or the silanes of the general formulae (III) are selected from the group of MeH2Si-SiH2Me, MeH2Si-SiHMe2, Me2HSi-SiHMe2, MeCI2Si-SiCI2Me, MeCI2Si-SiCIMe2 and Me2CISi-SiCIMe2, and/or the carbodisilanes of the general formula (IV) are selected from the group consisting of MeH2(SiCH2Si)H2Me, MeH2(SiCH2Si)HMe2, Me2H(SiCH2Si)HMe2, MeCI2(SiCH2Si)CI2Me, MeCI2(SiCH2Si)CIMe2 and Me2CI(SiCH2Si)CIMe2.
13. The process according to the previous claims, wherein step A) is carried out in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, optionally in the presence of lithium hydride.
14. The process according to the previous claim, wherein the compounds of formula R1 4PCI are formed in situ from compounds of the formulae R1 3P and R1CI, wherein R1 is as defined above, preferably R1 is R as defined above.
15. The process according to any of the previous claims 1 to 5, 7 and 9 to 24, wherein in step A) Me2SiHCI is produced by the reaction of Me2SiCI2 in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, or
in step A) Me2SiHCI is produced by the reaction of Me2SiH2 in the presence of at least one compound of the formula R1 4PCI, wherein R1 is as defined above, or
in step A) MeSiHCb is produced by the reaction of MeSiC in the presence of at least one compound of the formula R1 PCI, wherein R1 is as defined above, or
in step A) MeSiHCb is produced by the reaction of MeSiH3 in the presence of at least one compound of the formula R1 PCI, wherein R1 is as defined above.
PCT/US2018/051860 2017-09-20 2018-09-20 Process for the production of organohydridochlorosilanes from hydridosilanes WO2019060486A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0324091A (en) 1989-06-21 1991-02-01 Tonen Chem Corp Production of dialkylmonocholorosilane
US20120114544A1 (en) 2009-07-13 2012-05-10 Samsung Fine Chemicals Co., Ltd Organic chlorohydrosilane and method for preparing them
US20130172593A1 (en) 2011-12-30 2013-07-04 Kenrick Martin Lewis Synthesis of Organohalosilane Monomers From Conventionally Uncleavable Direct Process Residue
US20130172594A1 (en) 2011-12-30 2013-07-04 Kenrick Martin Lewis Synthesis of Organohalosilane Monomers Via Enhanced Cleavage of Direct Process Residue

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0324091A (en) 1989-06-21 1991-02-01 Tonen Chem Corp Production of dialkylmonocholorosilane
US20120114544A1 (en) 2009-07-13 2012-05-10 Samsung Fine Chemicals Co., Ltd Organic chlorohydrosilane and method for preparing them
US20130172593A1 (en) 2011-12-30 2013-07-04 Kenrick Martin Lewis Synthesis of Organohalosilane Monomers From Conventionally Uncleavable Direct Process Residue
US20130172594A1 (en) 2011-12-30 2013-07-04 Kenrick Martin Lewis Synthesis of Organohalosilane Monomers Via Enhanced Cleavage of Direct Process Residue

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